Artificial intelligence

Artificial intelligence, abbreviated as AI, in the Super Smash Bros. series refers to the intelligence of any computer-controlled (CPU) character (called computer players in-game) in the single-player and Versus Modes. In Versus Mode, players can preset the AI of a computer player with a level setting. In Adventure Mode, All-Star Mode, and Classic Mode, players can still set it to some degree with the modes' difficulty setting.

Difficulty levels

Artificial intelligence levels range from 1 to 9, with 1 being the weakest and 9 the strongest. Default CPU level in Versus matches is 3 for Smash 64 and Brawl, and 1 for Melee. In general, the level of an AI opponent determines how likely they are to follow through with a decision, as well as how fast they react, which results in the illusion of more skill - both a Level 1 and a Level 9 AI will decide to do something such as input an attack, but the level 1 will almost never do so, while the level 9 almost always will. Lower level CPUs are also unlikely to shield or dodge an attack; in Melee, they roll only for shifting directions, and in Brawl, they randomly and occasionally use their shield as their almost only form of defending. On the other hand, higher level ones almost always defend from attack, generally having good powershielding reflexes or dodging any attack when not in lag - the Brawl AI is the best example of this, where Level 9 CPUs can dodge almost any attack with one-frame reaction. Higher level ones also vary more between attacks: low-leveled ones just move around the foe and randomly input an attack, mostly being a ground attack or special attack, while high-leveled ones are by far more aggressive and rely more on stronger attacks such as aerials or grabs. Their recovery also improves from one level to other: CPUs at low levels tend to recover in a simple and predictable pattern with their up specials, or may not use them at all in Smash 64, while high-level ones in Brawl are capable of properly combining or alternating between different recovery techniques.

In Training mode, besides attacking, CPUs also have many other "modalities" that can be chosen, these being: Stand, Evade, Walk and Jump. When these are chosen, CPUs will act that way, allowing players to battle in different ways against them, and practice different types of techniques. In Smash 64 and Melee, these are set to a pre-determinated level, also referred to as "Level 0", while in Brawl, they can be chosen from 1 to 9 from the character selection screen as usual, which also improves their reflexes. For example, Level 1 CPUs on Stand will just take on whatever attack is thrown on their way, and recover in a simple and gimpable pattern, while Level 9 ones will almost always air dodge after tumbling and will choose better recovery options. When set at Attack, CPUs will fight the player as on usual battles, but while the level can be selected in Brawl, it is always Level 1 in Smash 64 and Melee, which makes it somewhat unfavorable to fight CPUs on Training mode. Players instead tend to train against them on normal Versus modes.

Certain 1-player stages and events in Melee give CPUs a level of 0, such as on the Peach's Peril and Ice Breaker events, where they don't attack at all, but still follow whatever movement behaviour they would normally have.

Training against CPUs

Players commonly fight against CPUs to train when there aren't other players around to play. This is a practice that is criticized by some, as besides even the highest level CPUs being of a lower level than a typical casual player, CPUs do things that human players never do (and will never do things that are common for human players to do), as well as having several exploitable flaws and being completely incapable of mind gaming. Training against CPUs does not adequately train one's cerebral skills (such as the ability to read and bait opponents), and it is often argued that excessive training against CPUs may cause a player to develop habits that work against CPUs but will be heavily exploited by human players. To give a basic example, if a Kirby player used Stone on a CPU persistently, it would be hit by the attack most of the time, without defending or choosing to do it too late. However, a skilled human player would easily avoid the attack by rolling, sidestepping, shield-grabbing or just walking away, and then punish Kirby with a grab or strong attack, such as a charged smash. Another example is CPUs not fighting off edge-guarders in any of the Smash games, which allows players to KO them with basic edgeguarding techniques, while experienced players would prevent this at all costs.

However, training against CPUs does have its merits. CPUs can be used to effectively practice combos and chain throws, as well as spacing, punishing attacks, and other tech skill related things. CPUs can be more effective than human players in this regard, as they're always available and won't refuse a match where a player just wants to practice the aforementioned things. Many top professional smashers have reported using CPUs to train, such as Nairo and Vinnie.

There is no consensus though on what level CPU is best to train against, with players mostly having their own personal opinion on what level is most effective. Some say level 1 CPUs are the best, as they won't have inhuman perfect shielding abilities and won't disrupt the player's training. Some say level 9 CPUs are the best, as they will actively try to fight the player and can punish mistakes the player makes. Some others say level 5 CPUs are the best for being a middle ground between the two extremes. Another camp maintains what level is best is dependent on what a player is trying to practice.

Flaws in the AI

While it is notable that high level CPUs are precise with their reflexes, such as being able to power shield almost any attack, reflect projectiles with little hesitation, counterattack out of knockback the instant they can act, and land or control attacks that human players would find difficult such as Yoshi's Egg Throw and Pikachu's Volt Tackle, all three games are known for having AI that can be extremely flawed in most scenarios, even when set to level nine. There are many complaints surrounding the poor artificial intelligence of computer players in Super Smash Bros. and Super Smash Bros. Melee, though Super Smash Bros. Brawl has also received attention to its flawed AI system; in all three games, particularly noteworthy and amusing AI flaws have been uploaded to YouTube, often by saying that the AI in the games is "just too good".

Super Smash Bros.

As being the first Super Smash Bros. game, the AI is considered poor even with CPUs set at level nine. When fighting, their main form of attacking is to constantly use a special attack, especially if it is a projectile, along with smash attacks. These include Mario constantly shooting Fireballs, or Jigglypuff persistently using Pound. Other than using tilts occasionally, they tend not to use other attacks, using neutral attacks and grabs rarely, though high-leveled CPUs do combine these two for a jab grab. When a player is at a considerable airborne distance, CPUs attack mainly by using an aerial attack depending on their distance from the enemy, which makes their attacks very predictable. This includes, for example, Captain Falcon and Fox constantly using their up aerials on a foe above them, and Samus repeatedly using her down aerial. When a player stands on a platform above them, CPUs with "jump" up specials may also attack with them, even if they aim them in such a trajectory that would make them fall onto a pit and self-destruct. However, CPUs still have good aiming abilities, such as precisely hitting with aerial attacks, as well as with attacks that may seem difficult for human players, such as Yoshi's Egg Throw.

Though these attack techniques are not considered as flawed as in Melee, CPUs in Smash 64 still have poor recovery abilities. For example, if a CPU uses their up special to recover after jumping, but the player attacks them out of the attack, the CPU will not attempt to use it again. This makes CPUs reliably easy to KO with meteor smash attacks. They also underutilise the recoveries of certain characters, and, at low levels, they may not use their up special to recover at all. In addition to this, they always recover in an extremely predictable way, always using their air speed to move towards the stage before using their up special, while never attempting to fight-off edgeguarders with aerials. Additionally, CPUs have poor defensive abilities: for example, when being attacked by a consecutive hitting jab (such as Kirby's), they just hold their shield in place after they use it, until it eventually breaks, without even attempting to escape the attack by rolling. They do use rolls outside that situation; however, after using the technique once, they heavily spam it, which makes easy for players to punish them with attacks like down smashes (especially Mario's and Pikachu's). Outside of this, however, grounded CPUs may still defend properly against attacks that may result difficult for humans, such as item-based attacks or quick ground attacks, as well as being able to tech succesfully in some stages when launched upwards. Also, Fox and Ness successfully attempt to use Reflector/PSI Magnet against an oncoming projectile; in Ness's case, when playing at Saffron City, he will successfully absorb Charmander's Flamethrower if he's not interrupted, something that may be difficult for humans to do. Despite this, CPUs still cannot recognise these techniques when used by players. For example, they may still throw items against a Fox player with an active Reflector, as well as still shooting absorbable projectiles against a Ness with an active PSI Magnet. Also, a CPU Ness may still attempt to use this move against a non-absorbable projectile, such as a Boomerang. CPUs additionally have almost non-existing edge guarding abilities: when knocking a foe offstage, they will just stand on the ledge and throw off their usual attacks whenever the foe comes near. Additionally, if a foe grabs a ledge when a CPU jumps in an attempt to attack, they will mostly decide to fast fall and attack with a down aerial, which, depending on the character, often causes self-destructs.

CPUs in Smash 64 are also well known for their tendency of using items. Regardless of the CPU level and item, when an item appears, CPUs cease fighting and go for it, mostly putting themselves in harm while doing so, especially because of the incapability to grab items on mid-air in Smash 64. The only exceptions are wandering Bob-ombs, and Starmen in some ocassions. They also underutilise certain items; they may still walk into their own Bumpers or Motion-Sensor Bombs, resulting on self-destructs. In some stages, they may also walk into traps, such as the tornados on Hyrule Castle. Additionally, when using a Fire Flower or Ray Gun, they attack only by shooting with them, and throwing the item after it runs out of ammunition, making their attack pattern predictable. The only exception is when battling against Fox or Ness: Level 5 and above CPUs only throw the item against them, never shooting, since they can reflect/absorb the projectiles. In Fox's case, however, his Reflector can still reflect the thrown item. Also, when using a Star Rod, CPUs still shoot stars against these characters. When a foe uses a Hammer or Starman, CPUs will stay away from the character and, in the Hammer's case, shoot projectiles depending on the situation. However, they may be still easy to hit in the air. Also, when a CPU uses a Hammer, and a foe is far away, the CPU will jump towards him, even if the other platform is elevated and there is a pit between them, resulting in the CPU self-destructing.

Additionally, CPUs tend to play strangely on some stages. While their behaviour seems to be normal on simple stages like Congo Jungle and Dream Land, they may experiment certain flaws in others. For example, CPUs in the Yoshi's Island stage won't recognise items dropped on the clouds, and they have difficulty recognising walls on stages like Peach's Castle and Saffron City, not jumping over them unless an enemy provokes them to. On Planet Zebes, they are also very easily KO'd by the acid, and on Mushroom Kingdom, they may go off-stage and SD attempting to dodge opponents.

It is a common misconception among Smashers who have not played Smash 64 that the AI in this game is better at KOing than in the later Smash games. However, this is just because of the CPUs' higher tendency of using smash attacks than in the subsequent games, such as by Donkey Kong and Captain Falcon frequently using their down smashes, as well as their perfect precision with aerial attacks that allows for unexpected combos, plus their ability of easily using techniques such as jab grab. This, exacerbated by Smash 64's powerful aerials and the incapability of air dodging, along with the much more powerful throws in the game, tends to cause speculations that the AI in this game is better at comboing and KOing, and therefore it is more powerful than in the other games. This is arguably not true, however, as CPUs in this game have poor concepts of numerous attacks, as well as exhibiting strange behaviours on complex situations, poor defensive maneuvers that involve spamming rolls and not attempting to dodge attacks when airborne, and an easily gimpable recovery that allows easy KOs to them. These flaws are over their rather powerful attack playstyle, highly endangering them and leaving them easily vulnerable against semi-professional players, or even some casual ones if they are able to predict their actions.

Therefore, because of these numerous flaws, and despite CPUs using attacks more moderately than in Melee, the AI in Smash 64 is considered as the worst of the three current Smash Bros. games.

Specific Examples

Other examples of flawed AI in Super Smash Bros. include:

• Other than not using their up special again after being attacked during their recovery, CPUs also underutilise certain character's recoveries:
  • When a CPU Captain Falcon grabs someone with his Falcon Dive during recovery, he will not attempt to use the move again as well.
  • CPUs always aim their recoveries towards the center of the stage; that is, if meteor smashed in stages such as Dream Land and Peach's Castle, no matter the strength of the attack, they will go underneath them and fail at coming back. Similarly, in Sector Z, they may aim recovery towards the Great Fox's cannons, which cannot be stepped on.
  • A CPU Ness will always aim his PK Thunder as a recovery in an horizontal, barely upwards angle, even if the ledge is above him.
  • A CPU Kirby and Jigglypuff will immediately use up all their jumps after getting knocked off the stage.
    • CPU Jigglypuffs additionally never use Pound to recover. At high levels, however, they may still use it if characters approach them from the side, in an attempt to attack.
• High-level CPUs usually taunt when they hit an opponent with a high knockback attack, even if it doesn't KO them. This means they can taunt even if there are traps or other players nearby, and even if the attack is a meteor smash that leaves the foe at a short distance from the CPU. This makes it easy to punish characters with long taunts, such as Mario.
  • Additionally, if a CPU in midair sends a foe far away, and then quickly grabs a ledge, it will taunt as soon as it gets up.
• High-level CPUs almost always start the match using a move like a down smash, being extremely predictable. If the player doesn't approach them, they may use that same move continuously while moving a very short distance forward each time.
• High-level CPUs tend to make persistent use of a special move depending on the character, especially if it is a projectile attack, preventing them from using other attacks moderately. This includes:
  • CPU Mario and Luigi persistently shoot Fireballs against players at a distance from them. CPU Ness experiments the same behaviour with PK Fire, as well as Pikachu with Thunder Jolt. This makes it easy for an experienced Ness player to have a large advantage against these CPUs by absorbing the attacks with PSI Magnet.
    • Also, though CPU Kirbys use their attacks moderately, they may still spam any of these copied attacks.
  • CPU Donkey Kongs almost always charge up a Giant Punch and cancel it when the player comes near, almost never approaching or using another attack instead. CPU Samus behaves similarly with Charge Shot, constantly cancelling it and only shooting if a player comes in front of it.
    • Additionally, Donkey Kong mostly uses Spinning Kong to repel enemies at its sides instead of other attacks, and also chase the player after the attack is executed, even if this results on the CPU falling off an edge and self-destructing. This is more noticeable with Giant Donkey Kong: he tends to use Spinning Kong when the player's teammates approach him. CPU Links behave similarly with Spin Attack, though they very rarely self-destruct when doing so.
  • CPU Jigglypuffs tend to make constant use of Pound to attack players, especially on mid-air.
  • A level 9 Link will almost always use Boomerang as its first attack, as well as mostly using it when the foe is at a considerable distance. They may also use the move even if the boomerang was already thrown.
  • CPU Foxes tend to aim Fire Fox against players as one of their main attacks. As a result, if a human player runs to the edge of a stage such as Dream Land, Fox will follow him/her and aim his Fire Fox off of the stage - resulting in a self-destruct.
    • Similarly, if a character is far away from it, a high-level Fox CPU may repeatedly use Blaster, even if the enemy is shielding or protecting. This allows players to trick the CPU easily by absorbing the shots with Ness.
  • CPU Yoshi and Captain Falcon may also use Yoshi Bomb and Falcon Kick constantly against a player below them when airborne, but not as often as the other mentioned CPUs. This can still be potent, however, as they use these moves even when platforms are below them.
    • Additionally, CPU Captain Falcon will almost always jump before using Falcon Kick, which can sometimes cause the attack to miss and become easily punished due to its lag. If the player stays above him during the jumping phase, he will use Falcon Dive instead, falling helpless and becoming easily vulnerable.
• On the Kirby Team in the 1P Game mode, when the Kirbys are knocked off the stage, they tend to fast fall as soon as they run out of mid-air jumps, without even using Final Cutter to recover. This makes easy for players to KO them, even at Very Hard difficulty.
• CPU Marios and Luigis never rise when using Mario Tornado and Luigi Cyclone, respectively.
• A CPU Kirby using Inhale will only spit out the opponent if it is another Kirby, and in this case they also won't attempt to steal copy abilites from them.
• When invincible, such as by the effect of a Star of when dropping out of a revival platform, CPUs will still shield and dodge attacks thrown against them. Additionally, when a player comes out of a revival platform they may still attack them during their invincibility period.
• When returning on a revival platform, CPUs always reenter the fight instantly regardless of what is happening on the stage. This can result, for example, on an opponent using a Hammer being more difficult for them to evade, while staying on the revival platform would have been more desirable.
• A CPU player who picks up a throwing item when another player is below their platform will repeatedly throw the item to the ground until it disappears - even if the item is a Bob-omb, which often leads to the CPU self-destructing.
• Other than regular items, CPUs will also attempt to go for Bombs left by a Link player. Not only they will cease fighting for this, but they may pick up the bomb even if it's about to explode.
• When a Bumper is set, a CPU Fox or Ness may hold his Reflector/PSI Magnet near it until it vanishes, he gets hit, or another item appears.
• When standing on moving platforms, CPUs usually won't be conscious about the danger and will stay there like on a normal terrain, which mostly results on them not jumping off and going offstage with the plaftorm, guaranteeing a self-destruct. This can happen, for example, when a CPU comes to attack a foe on the balancing plaftorms at Mushroom Kingdom, or when landing on an Arwing during recovery at Sector Z.
  • Additionally, if a Crate or Barrel falls on one of the balancing platforms at Mushroom Kingdom, CPUs will still attempt to pick it up, falling down with it and SDing.
• As mentioned above, CPUs have difficulty recognising walls. If there is a player on the right side of the Saffron City stage, CPUs will walk into the doors of the Pokémon trap. Similarly, on Peach's Castle, if a human player stands on the bottom platform, a CPU on one of the moving platforms will run into the wall repeatedly.
• On Saffron City, if the player is Player 1 while a level nine Pikachu is set to Player 2, if the player stands on the left edge of the rightmost building after Pikachu is KO'd, it will jump off the revival platform to the right and then approach with Quick Attack, overpassing the building and self-destructing. This can be exploited indefinitely as long as the CPU is not interrupted by something.
• In Dream Land, if a player stands below a CPU Donkey Kong on a platform, it will continously use Hand Slap until the player gets out of there, leaving it easily open for aerial attacks.
  • In a similar scenario, standing on a Dream Land platform above a CPU Yoshi will cause it to use Egg Throw, which (when shielded) will be inevitably followed by an infinite stream of double jump canceled up aerials that are nowhere near hitting the player.
• In Mushroom Kingdom, CPUs will never attempt to intentionally use the POW Block nor the Warp Pipes.
• In most cases, a CPU Kirby using Stone holds the attack in place instead of ending the transformation by itself. When the attack is used on a slope, such as that of the leftmost part of Hyrule Castle or at the far right side of Sector Z, it may hold the move in place, falling down and self-destructing.

Super Smash Bros. Melee

The AI in Super Smash Bros. Melee is notorious for how flawed it is. Computer players, regardless of level, primarily fight by constantly approaching to then spam their neutral attack and dash grabs when close to opponents, while periodically using any projectiles they have when opponents are out of the range of their jab and grab. In Kirby's case, CPUs repeteadly use Final Cutter to attack, and with Bowser, they may use Fire Breath even if the foe is out of the move's range. Though the exact rates of usage vary depending on the character, the AI will generally avoid using their tilts and smashes outside certain situations, and will almost never use aerials to attack unless they were already in the air from trying to reach an opponent's position (such as if they were jumping up to an opponent on an upper platform) or from being hit into the air from a prior attack. For this case, they also tend to use their neutral aerials over other types of aerials, not using the latter ones unless the foe is at the proper distance. Specific CPUs also have a tendency to overuse one move aside from the aforementioned, such as Ganondorf constantly using Dark Dive when a character is in front of or above him, and Zelda constantly using her down tilt to "lock" opponents. Some characters also have their own "playstyle": a CPU Mr. Game & Watch rarely uses projectiles and instead approaches mostly with his dash attack, a CPU Yoshi uses Egg Lay as often as his grab, CPU Pikachus and Donkey Kongs frequently use their forward smash on a foe at a close distance, and CPU Ice Climbers don't grab as often and instead just struggle with their jab as their main attack. The AI is additionally notorious for how terrible it is at recovering. While the AI won't give up during recoveries like in Smash 64, the AI still has significant problems with its recovery skills. The AI always recovers in a basic and predictable pattern, which itself causes them to fail many recoveries that were possible, while making no effort at all to fight off edge-guarders. This results in computer players being extremely easy to edge-guard, which is exacerbated by Melee's edge-guarding friendly physics. CPUs have, however, precise meteor cancel abilities, so that it they are hit by a meteor smash during recovery phase, they almost always meteor cancel the attack (though if they are meteor smashed during their recovery move or near the stage ledge, they will usually not meteor cancel). A CPU Kirby or Jigglypuff, for example, will meteor cancel almost any attack, even Ganondorf's down aerial at 100% damage. Interestingly, they meteor cancel like this even at Level 1. Despite this, they are very easily KO'd by other edge-guarding abilities, such as walls of pain or spikes.

The AI in Melee also make poor use of their shields and defensive maneuvers in general. Computer players, even at level nine, will often not use their shields to block attacks, and will often not use rolling dodges, sidesteps or air dodges to dodge attacks. As such, computer players will often take whatever attack is thrown their way, expending no effort to dodge it, and when combined with their constant approaching, will often lead to them just walking into a player's charged attack. There is an exception to this though with a few attacks that the AI was programmed to dodge at all costs, such as Bowser's up smash and Bowser Bomb, where computer players will always roll dodge away or air dodge if the attack is being used in their vicinity. This can be observed by charging Bowser's up smash below a CPU, where it will always air dodge away from the attack, or, if on a platform, will roll back and forth until Bowser unleashes his smash. Other examples also include Yoshi Bomb, Raptor Boost and the last hits of Dancing Blade, where they avoid them the same way. Additionally, despite minimal use of their shields, CPUs are very precise with power shielding, so when they do shield an attack, it is usually a power shield. On top of this, while the AI will often not shield physical attacks, higher level CPUs will always shield any projectile if they are not in lag; level nine CPUs will usually perfect shield to reflect projectiles. They do this to a fault however, which can be exploited with rapid projectiles like Blaster, as when under projectile fire, CPUs will prioritise shielding against all projectiles over all else, leading to the CPU just standing there and shielding against rapid projectiles until the opponent ceases fire or they break their shield. Like in the previous game, CPUs also have poor edge-guarding abilities, as they will just stand on the ledge and use their main attacks whenever the recovering foe comes near, and still have a chance of self-destructing in an attempt to attack ledge-hanging players when on air. While there were better chances of the CPU getting a KO in Smash 64, this is rarer in Melee, since jabs and throws are usually not powerful enough to launch the foe into the blast line, and instead they allow the foe to jump and recover again. Some characters like Mario, however, will jump offstage and attempt to edge-guard with their meteor smash attacks: while this has a sure chance of KOing, they always jump horizontally and then pull out the attack in the same way, which, combined with the usual lag of meteor smashes and poor recovery of CPUs, makes it easy for recovering players to dodge, while often causing the CPU to self-destruct, especially when metal.

Certain stages are notorious for exploiting poor AI, such as stages with pits like Jungle Japes, where the AI does not properly recognise these pits and will often fall into them to self-destruct while trying to attack a player near them. The AI also plays especially poorly on moving stages such as Icicle Mountain, where computer players will move up one platform at a time, which is too slow to escape the lower blast line when the stage speeds up.

The AI is also extremely incompetent with handling items and their effects. When their physique changes, the AI will ignore the changes and will play as if they were normal, which leads to giant CPUs inadvertently walking off stages, and metal CPUs plummeting to their death as they attempt to attack an offstage player. When an item appears, CPUs will never pick them up, only picking them up accidentally when trying to attack an opponent next to the item; additionally, they have poor concepts of knowing what items are in front of them, frequently causing them to walk into set Motion-Sensor Bombs, walking Bob-ombs, and into hostile Poké Ball Pokémon. When picking up battering items (except for the Hammer), the AI still acts and fights as if not wielding it, which often leads into CPUs jabbing with the item persistently and then dropping or throwing it in an attempt to grab opponents. There is an exception to this when there are healing items, Poké Balls, Cloaking Devices, or Hammers present; CPUs will usually immediately cease all fighting against the player and will instead flee to pick up these items. They will often put themselves in harm's way while trying to do so, just to obtain said item. Additionally, they don't attempt to grab items while in the air, so that if the item falls on a platform, for example, the CPU will pick it up only after landing on it, while a human player would air grab it from below, making easy to "steal" items from CPUs.

Specific Examples

Specific examples of poor AI include:

• Computer players have generally poor recovery abilities:
  • They will never attempt to fight off or evade edge-guarders.
  • They will only use their midair jumps and up special move to recover - never any alternate recovery methods such as side special moves, air dodges or wall-grapples (as they don't use grab aerials).
    • Luigi acts as an exception; he will instead always use the Green Missile and never use Super Jump Punch to recover, even when necessary. They also never charge it, so they mostly fail to recover if the attack is not a "misfire", though they do use the move periodically. Still, this leads to CPU Luigis self-destructing easily on stages that emphasise vertical recoveries, like Mushroom Kingdom II or Brinstar Depths.
  • CPU Fox, Falco, Marth, Roy, Zelda, and Mewtwo, and Shiek will always aim in the same upward diagonal trajectory when recovering, even if using such a trajectory will result in them failing to make it back to the stage while a more desirable trajectory would allow them to recover successfully.
  • If a CPU Jigglypuff runs out of midair jumps when recovering, it will use Sing, instead of using Pound or an air dodge, guaranteeing a failed recovery.
  • A CPU Ness will use PK Thunder only when recovering if they are set to level nine, and will always aim it in an upwards, barely horizontal trajectory. A lower level CPU Ness will just fall and get KO'd if their midair jump is not enough to make it back to the stage.
  • CPU Peaches will rarely use the ability to float; they most often use it near the bottom of the stage, simply stalling their eventual fall. CPU Peaches also tend to use Peach Parasol to recover immediately when close enough to the edge, even when the superior midair jump is available.
• Computer players have poor concept of continuous attacks:
  • They never charge attacks that require button holding, including smash attacks (with the exception of the Ice Climbers, who occasionally charge their forward smash), Shield Breaker, Hero's Bow, Skull Bash, Green Missile, Rollout, and the Super Scope, among others. Zelda with Din's Fire (depending on the foe's distance) and Sheik with Needle Storm are exceptions, though. Also, if a CPU Ness uses PK Flash and the player comes at its side, it will fully charge the attack.
  • They never use the second hit of Link's or Young Link's forward smash; as a result, CPUs cannot KO effectively as either character, as Link's forward smash is relatively weak when the first hit connects, while Young Link's first hit deals low, set knockback to set up the second, more powerful attack.
  • CPUs never hold infinite attacks such as rapid jabs, Fire Breath, Reflector, Inhale or Hand Slap past their minimum length. They also never hold the Fire Flower's flames. They also do not charge or fire the Super Scope continuously.
    • When approaching, a CPU Bowser (and also Giga Bowser) also periodically uses Fire Breath even if completely out of the opponent's range, making them very predictable and easy to counter.
    • Similarly, a CPU Sheik may periodically use Chain when approaching, instead of Needle Storm, making it easily vulnerable against attacks. They also rarely swing the chain around, and only if the opponent is close to them.
  • A CPU Kirby under the effect of Stone will never end the transformation early. Besides allowing players to easily punish a CPU Kirby with powerful attacks, this will cause him to self destruct on some stages, if he hits a breakable platform above the lower blast line or is on a slope that ends offstage, cause him to slide down and off to the lower blast line.
  • CPU Marios, Luigis and Dr. Marios never move around nor rise when using their respective down specials.
• CPU Kirbys have unusual behavior dealing with Inhale. When they first use Inhale, they will constantly use it until they can copy a character. Additionally, they will heavily spam the move they copied. They also never move around with swallowed foes and spit out an opponent only if it is another Kirby. In this case, they also always spit out the Kirby, even if it has another copied ability that can be stolen. If a human-controlled Kirby swallows a CPU Kirby without an ability, the CPU Kirby will almost always use its Stone ability, allowing the human Kirby to rack up damage by repeatedly swallowing the Kirby.
• CPU Peaches, Luigis, Pikachus and Pichus tend to use their side specials against foes at a distance between close and far from them, not charging them for the latter three (as noted above). While not seemingly problematic, they can be easily punished if the attack misses, and for Luigi's case, he may self-destruct on small stages if the attack becomes a misfire.
  • As an additional flaw, if a CPU Peach comes offstage with Peach Bomber, she will float, despite not usually doing so. However, she will always hold it to its maximum length, and will unusually not move around when doing so, which can allow the player to easily edge-guard her.
• CPUs will always throw a grabbed opponent in a random direction, which, combined with their exploitation of the technique, results in edge-guarding CPUs throwing the foe into the stage, or using a throw when another one would have KO'd the foe. Some CPUs also tend to overuse a type of throw, such as Fox frequently using his down throw, or Mario and his clones mostly using their back throws.
• A CPU Marth or Roy will never use Counter.
• A CPU Zelda will never use Nayru's Love, not even for reflecting projectiles. A CPU Kirby with Zelda's ability still uses the move, though.
• A CPU Mr. Game & Watch never uses Chef. Also, the Mr. Game & Watch uses Oil Panic at inappropriate moments.
• CPU Ness never uses PSI Magnet, even when projectiles are shot in their vicinity. They instead just reflect them by powershielding.
• A CPU Jigglypuff never uses Rollout or Rest. Strangely, a Kirby with Jigglypuff absorbed will attempt to use Rollout, but will never charge it when using it (as noted above).
  • Additionally, a CPU Kirby with Jigglypuff absorbed may use Rollout even if near a ledge, which would cause it to fall down in helpless state and self-destruct. As CPU Kirbys mostly spam copied abilities, this can be easily exploited.
• CPU Links and Young Links will never attempt to angle their Boomerangs.
• When a CPU Marth or Roy uses Dancing Blade or Double-Edge Dance, respectively, it always executes the four hits in a single attack, even if the player gets out of its reach. They also never use the up and down combinations of the attack.
• A CPU Samus will only use Bomb when above a foe in mid-air.
• As they approach the player, CPU Captain Falcons and Ganondorfs will periodically use Falcon/Warlock Punch, Raptor Boost/Gerudo Dragon, and up tilt in the case of Ganondorf, like how other CPUs use projectiles while approaching. They do this despite the opponent being completely out of their range, and the very long lag of these attacks making it easy for opponents to punish them. They will occasionally use Falcon Kick/Wizard's Foot instead, however.
  • CPU Captain Falcons will additionally always use Raptor Boost after using forward throw (or sometimes down throw) on someone, even if it would cause them to go offstage and self-destruct. They may also use Raptor Boost if the player is near the ledge offstage, attempting to hit them, but usually falling off the stage. CPU Ganondorfs however do not exhibit this behavior with Gerudo Dragon.
  • CPU Ganondorfs will also nearly always use Dark Dive when someone is near above them, even if they're near the edge of the stage, which can cause him to use Dark Dive and then fall offstage, self-destructing. CPU Falcons however do not exhibit their behavior with Falcon Dive.
• CPU Kirbys and Bowsers will mostly use their down specials (Stone and Bowser Bomb respectively) on foes below them when they are in midair, regardless of what is below them. Similarly, some grounded CPUs will spam a special attack if a player is above them: a CPU Ness will spam PK Flash, a CPU Pikachu or Pichu will spam Thunder, and a CPU Peach mostly uses Peach Parasol if the player is at a close range. CPU Yoshis may also use Egg Throw in a similar way.
  • Additionally, when CPU Peach uses Peach Parasol as an attack, she will follow the player even if near a pit, making Peach approach it and then, depending on the stage, not being able to reach a platform or ledge, resulting in a self-destruct.
• A high level CPU Yoshi mostly uses Egg Roll against a player at a large distance, and chase them even if near an edge, so that if the player shields or dodges the attack, the CPU may easily fall offstage and self-destruct.
• When using PK Thunder as an attack, a CPU Ness will always aim it in a diagonal or horizontal trajectory, and will not send it back even if it misses the foe, leaving it highly vulnerable against attacks. When getting close to the foe, they also heavily spam PK Fire.
• CPUs will never initiate a fast fall intentionally, only doing it sometimes when attempting to attack with a down aerial while falling down.
• AI have poor taunting habits. After the CPU respawns, if the player jumps for a distance while the CPU is walking toward them, the CPU may eventually taunt for no apparent reason. They don't do this if they haven't KO'd an opponent, though.
  • Upon KOing a character, CPUs will usually taunt, regardless of what is occurring around them.
• CPUs will never initiate a dash outside dash grabs and/or dash attacks, the latter being less common. They also act almost immediately after the initial dash, which makes their attack pattern predictable and easy to avoid.
• Like in Smash 64, CPUs will still shield attacks when invincible, and still attack other opponents during invincibility period of a revival platform. When returning on one, they also reenter the fight instantly, regardless of what is happening.
• CPUs will never sidestep intentionally; the only time they will sidestep is when they are trying to both shield and crouch (either for an attack or for dropping through a platform) at the same time.
• While CPUs always attempt to dodge certain attacks (as noted above), their dodging capabilities can still be exploited. For example, a CPU near an edge attempting to dodge an attack such as Bowser Bomb may roll towards the edge, which can result in the attack hitting and KOing the CPU while it would have survived with another dodging technique.
  • When air dodging, CPUs also tend to shift themselves into the direction they were previously moving, even if it causes them to collide with the attack they were trying to dodge.
• CPUs never attempt to intentionally execute wall or ceiling techs. They also randomly use ground techs, and only do so if they are sent at an upwards distance and are not interrupted when reaching the ground.
• Unusually, other than Fox and Falco using their Reflectors, CPUs always reflect projectiles with powershields only, even though some characters like Mario and Zelda have stronger reflectors that last for a longer time. This results in things such as CPUs not being able to properly reflect Poké Balls (as powershielding them does not change the Pokémon's owner) or consecutive projectiles, or their shields becoming easily broken by rapid-fire projectiles.
• When an opponent is knocked down or hanging on a ledge, CPUs will only use down tilts and down smashes to attack them, even when some like Captain Falcon's down smash don't reach ledge-hanging foes.
• CPUs cannot properly recognise the height differences that occur when standing on slopes, which will lead to things like a CPU flailing above an opponent with their jab when higher up on a slope.
• CPUs do not recognise pits as if they were an offstage area, leading to the CPU just walking into them and falling into them as the CPU attempts to carelessly attack an opponent near the pit, which often results in the CPU self-destructing.
• A CPU Mario and Dr. Mario, regardless of the level, will often jump offstage and attempt to use their forward aerial to edgeguard against recovering opponents, which depending on the stage, frequently leads to self-destructs. The rightmost side of Corneria is a good example of this. They also always jump horizontally and attack in the same pattern, which makes them predictable and very easy to avoid.
  • CPU Captain Falcons exhibit similar behavior with their down aerial, though they rarely self destruct when they do so. Despite this, they are still easy to dodge since they always attack in the same way, and they will self-destruct easily when giant or metal.
• Despite the AI's tendency to shield any projectile as noted earlier, CPU Bowsers will never shield projectiles when approaching the player, even at level nine.
• Picking up either a Hammer or a Starman will cause all the CPUs to run to the opposite side of the stage and stand there until the effect wears off; they will not use any defensive maneuvers whatsoever.
• When using a Warp Star, CPUs will never change the trajectory of the attack.
• If a CPU grabs a Hammer, it will chase opponents until they reach a wall and continually jump in place even if the obstacle can be jumped over. They will also jump offstage to chase opponents that have jumped off the stage, and self destruct in the process.
  • Additionally, even if the Hammer's head falls off, CPUs still attempt to chase opponents, putting themselves in harm while doing so. They also never pick up the head intentionally, as with other items.
• If they are next to the radius of Venusaur's earthquake or near Wobbuffet, the CPUs may shield even though they are not in the Pokémon's damage radius. Unusually, they may also hold their shields in place, which can result on a self-shield break, and a SD to Jigglypuff. This is noticeable with the Wire Frames on the Legendary Pokémon event.
  • Additionally, if a CPU is knocked on the air near Venusaur or goes above it to approach a player, it mostly uses an instant air dodge, even if it can just be jumped over.
• When the player stands still on certain locations in stages, all opposing CPUs will cease all movement and action if the player is not in attack range, until the player moves or one of the aforementioned desired items appears. A notable example of this is the right edge of the middle right platform in Battlefield, which can be exploited in Cruel Melee.
• In Princess Peach's Castle, CPUs will always run to the opposite side of the castle when Banzai Bill appears. During this, the CPU will ignore opponents, and will not attack nor defend themselves unless an opponent comes near. When this does happen, it disrupts their normal behavior pattern and they will sometimes stay on the side of the castle where the Banzai Bill is and get KO'd by its explosion.
  • Also, CPUs may run straight into the Banzai Bill in order to reach the other side.
• In Brinstar, CPUs will always go to the hovering metallic platform in the centre when acid rises from the bottom. During this, the CPU will ignore opponents, and will not attack nor defend themselves unless an opponent comes near.
• When at a stop on Mute City and the stage is about to move again, they will not jump back on the main moving platform unless a player or item provokes them to go on it, leading to them sustaining avoidable damage when the stage moves.
• In Jungle Japes when the player is Player 1 while a CPU Ness is Player 2, if the player does not move, Ness will try to jump over to the player, but will fall into the river, and self destruct his first stock. Even at Level 9, his PK Thunder would be blocked by the left platform.
  • Also, if the player stands still on the right platform as a CPU Fox comes off the revival platform in this same stage, Fox will repeatedly jump into the river, use Fire Fox below the center platform and fail to recover until he runs out of stocks or time runs out. A CPU Roy will also exhibit this behavior in this situation, aiming his Blazer to the left, missing the ledge and self-destructing.
• For an unknown reason, high-leveled CPUs on Fourside tend to air dodge on the pits, which depending on the character, mostly leads them to self-destructs when doing so. A notable example is Yoshi, who, if selected as Player 2 to start from the rightmost building, will always air dodge above the first pit and self-destruct.
• On Green Greens, whenever a player meteor smashes a CPU, it will aim its recovery to the center of the stage even if the blocks don't allow to, or even if it's launched closer to the edge of the stage, resulting on self-destructs.
• On Mushroom Kingdom II, when battling against a level 9 Luigi set as Player 2, if the player KOs him and then goes to the right part of the stage, Luigi will jump backwards from the revival platform and miss the ledge, and then use Green Missile on the wall and self-destruct. He repeats the process over and over again if the player keeps there at a distance from the ledge, unless he is interrupted by a platform, Birdo's eggs, or an item.

Super Smash Bros. Brawl

In Super Smash Bros. Brawl, the AI is generally more proficient with character recoveries (most prominently Luigi). If a human player gets an item like a Starman, rather than just trying to avoid that character, they'll also use the opportunity to attack any stragglers. When a Smash Ball appears, computer players will aggressively attack it at opportune times, while repelling anyone who tries to get it as well. They also recognize and use other items (like the Super Scope) as well, unlike in Melee. Additionally, CPUs can now properly charge up or hold smash attacks and special attacks, among others, and choose more alternatives when using certain attacks, such as Kirby spitting out characters more often, Link using his grab aerial and the second hit of his forward smash, and Donkey Kong throwing foes upwards and/or downwards with his cargo throw instead of just forward. CPUs can now properly use aerial attacks against grounded foes rather than just attacking from land, and often punish attacking opponents with shield grabs. Another significant change in AI is that computer players have a preference to targetting human players before other computer players. Their taunting habits are less flawed than in Melee, as they don't use them if there are other enemies or obstacles, and they won't taunt if the player just escapes from them after they respawn. Additionally, CPUs in Brawl are much better at defending, as they sidestep and roll more often, and, with the change of air dodges, also use this technique properly, as well as being almost impossible for a human player to break a CPU's shield, and high-level CPUs almost always teching on any solid surface when launched a high distance. Plus, when a Hammer, Starman or Final Smash is being used by a foe, CPUs will just stand on their revival platforms if they were KO'd, instead of just reentering the fight instantly like in the previous games. Another notable change is that, when a high-valued item appears, instead of just ceasing fighting to go for it, CPUs now try to repel any other character trying to get it, and if it appears too far from them, they will just ignore it and battle as usual (except for the Smash Ball).

Another new feature is that the computer's level in Training Mode can now be selected. The AI is improved greatly, as opponents set to Attack mode will actively fight the player, rather than walking towards them and rarely throwing an attack like in previous installments. Other CPU modalities can also be improved by raising the AI level.

Also, for each CPU level, the game gives a word to describe the CPU's skill level:

1. Puny-1
2. Wimpy-2
3. Weak-3 (the default level)
4. Normal-4
5. Hardy-5
6. Strong-6
7. Burly-7
8. Mighty-8
9. Nasty-9

Many rumors have circulated about the AI of Brawl. One claims that level 9 CPUs read button commands the player inputs, thereby allowing them to perfect shield and air dodge more often. This sparked general dislike among the community, many of whom labelled the idea as "cheating". There has been no evidence however that the AI reads the player's inputs, and "evidence" presented for it has just shown that the AI has 1 frame reactions.

Another rumor claims that there's a system in Brawl that enables AI players to "learn" from human players. All is Brawl blogger Churro Emiliano documented much of this widely for the first time in a blog post made at the end of 2008. Aside from some advanced techniques (such as dash dancing and QACing) and play-styles, the AI have also been reported to "learn" to taunt a KO by crouch-spamming, and to overuse Falcon Punches after humans play several Falcon Punch free-for-alls. It is currently not confirmed if there is a learning mechanism or not.

The flaws in Brawl's artificial intelligence are considerably lesser and less recurrent than in Melee, but they can still be potent. Computer players still tend to be easier to KO and edgeguard than the average human player, even when set at level 9, due to not utilising survival techniques such as DI and usually not fighting back when being edgeguarded. CPUs do, however, air dodge when sent flying, which provides minimal cushioning for knockback although usually not enough to save them. Computer players sometimes have difficulty avoiding certain stage hazards (most notably on Halberd), and are prone to self destructing in scrolling stages, such as the Melee Stages Rainbow Cruise and Big Blue. They have generally poor edgeguarding abilities (though unlike the previous two games, self destructing while attempting to edgeguard is very rare), and will usually stand on the ledge and spam projectiles when the player is recovering; they will usually attack offstage intentionally only with characters that have multiple jumps, such as Meta Knight. And while they are better at recovering than in the previous game, computer players still under-utilise recoveries, such as by not making use of alternate recovery options with some characters, or always recovering in the same direction with a recovery move. A computer player (regardless of level) will also always aim for solid platforms that can be sweetspotted when recovering, even when there are "soft" platforms off the stage.

Computer players additionally tend to play strangely in complex custom stages, and in overly large complex stages like New Pork City and 75 m. And, despite recongising items and using them better than in the previous installments, they may still self-destruct with certain items, such as by walking into a row of Bob-ombs when approaching a player, self-destructing with their own Electrodes or, when the player is at a large distance, accidentally shooting projectiles into a Blast Box and being KO'd by it. They still seem to ignore when Team Attack is on, continuing their assaults even when allies are in harms way as though team attack was off, which can cause them to hurt or even KO their own allies.

Aside from being flawed as stated above, in Free-for-alls, CPUs will all target the human player even if they aren't teamed. They will also target the character that has the highest damage to earn a KO, and in doing so will not attack other CPUs, which results in them following each other in lockstep.

Specific Examples

Specific examples of poor AI include:

• CPUs still underutilise the recoveries of several characters:
  • A CPU Ness and Lucas will always hit themselves with PK Thunder in the same upward diagonal trajectory when recovering, even if using such a trajectory will result in them failing to make it back to the stage while a more desirable trajectory would allow them to recover successfully. This is especially noticeable on Final Destination, as Ness will often not make it back to the stage when using PK Thunder to recover (when recovery is possible), while a Lucas will often launch himself underneath the stage lips.
    • A CPU Lucas will also never use his zair for recovery.
  • A CPU Ike will not use Aether unless he is directly underneath a ledge. This causes him to self destruct without trying to recover, or waiting too late to use Aether and failing a recovery that was possible. CPU Snakes exhibits similar behavior using Cypher, often choosing to use it too late and self destructing.
  • A CPU Yoshi will never use Egg Throw for recovery.
  • A CPU Luigi will never use Luigi Cyclone for recovery, and never rise with the move in any other situation.
  • A CPU Meta Knight will never use Mach Tornado nor Drill Rush for recovery, and will often use Dimensional Cape to recover instead of Meta Knight's other superior recovery options.
  • A CPU R.O.B. will not input any actions after using Robo Burner until it reaches the ground, grabs a ledge, or is hit by an attack.
  • If an opponent jumps offstage in front of a Fox or Falco using their up specials during the charge up phase of their move, they may angle the attack against the foe instead, even if it results in missing the ledge and self-destructing.
  • If a CPU Mr. Game & Watch uses Fire and fails to recover, he will repeatedly use Judge until the bottom blast line is crossed. While not necessarily problematic, there are instances where if a CPU Mr. Game & Watch reaches the apex of Fire and ends up short of the stage but in distance of reaching the ledge, the CPU will decide to use Judge too soon, causing him to miss the ledge and self-destruct.
• If a CPU KOs a player, while the player has invincibility frames after respawning, the CPU will run away from the player and jump onto a platform if there is one nearby, without trying to dodge the player's attacks.
• When players grab the ledge, CPUs will stand still a safe distance from the ledge for some seconds before pursuing the ledge hanging player.
• If a CPU, regardless of level, is hit near the upper blast line while above an elevated platform, they'll fall straight down until reaching the ground after knockback is finished, while making no attempt to dodge or counterattack a pursuing player.
• When hit by an electric hitbox, a CPU may randomly DI up or down, more often DIing down, which can result in instances of an attack with an electric hitbox KOing them when the computer player would have survived otherwise.
• While CPUs in Melee could meteor cancel to a moderate degree, CPUs will never meteor cancel in Brawl, sustaining the meteor smash's full knockback before attempting recovery. This results in meteor smashes KOing computer players at much lower percentages than they KO human players.
• When grabbing ledges, CPUs often decide to jump from the ledge instead of choosing other options, which can make them predictable and easy to edge-guard.
• CPUs have difficulty recognising walls.
• When using the Fire Flower, CPUs never hold the flames past their minimum length. CPU Bowsers and Charizards replicate the same behaviour with Fire Breath and Flamethrower, respectively.
• When Snake uses his down throw near an edge on a CPU, the CPU will always roll toward the nearest edge the instant they can make a move. This allows him to infinite them or get an easy KO with an up tilt. When done in a soft platform without grabbable edges, they will instead always use a floor recovery attack.
• If a CPU Snake plants a C4 sticky on an opponent, it will always move a small distance away and use Cypher, then detonate the C4 after. This makes them extremely vulnerable, predictable, and punishable. If attacked out of the Cypher, they will simply run away a short distance and then detonate the C4.
• When Ganondorf uses Flame Choke on a CPU, they will never act the soonest they can.
• A low leveled Fox, Falco and Wolf will mostly self-destruct when using Landmaster, especially if the target is hanging on a ledge or so. A high level CPU will stay in place and repeatedly perform barrel rolls against opponents grabbing the ledge. Also, regardless of the level, they won't attempt to Star KO enemies above them by rising, only doing it accidentally when rising on small stages like Flat Zone 2.
• When a CPU Luigi uses Negative Zone, he will almost always spam Fireball, even when set to level nine.
  • Similarly, a CPU Pit using Palutena's Army will spam Palutena's Arrow.
• CPUs with a Gooey Bomb or C4 stuck on them will repeatedly shield and dodge until it falls off or explodes.
• Despite their better recognition of items, CPUs still experiment several flaws when using the Hammer, as in Melee. They still tend to accidentally fall offstage when trying to attack a foe near a ledge and, when on an elevated platform, jump continously in place even if the obstacle can be jumped over. This is however less common with the Golden Hammer. CPUs also still chase foes when using a Headless Hammer or Golden Squeaky Hammer.
• CPUs holding a Cracker Launcher will not turn around, and will shoot at a slow rate in their current trajectory while repeatedly stepping back if their targeted player is not in front of them.
• CPUs holding a Team Healer will always aim it at their enemies and never their own teammates.
• In the underground version of Mushroomy Kingdom, CPUs will sometimes repeatedly attack the blocks, ignoring the player even if items aren't on.

External links

• A playlist of videos showing the many flaws and exploits of the AI in Melee and Brawl.
• The majority of TAS videos by Andtgar show off abusing Smash 64 AI while perfectly comboing.
• A video showing many AI flaws in Melee, some of which are listed above.
• A video showing an AI flaw of Falco in Melee.