Artificial intelligence

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

Artificial intelligence levels range from 1-9, with 1 being the weakest and 9 the strongest.

Criticism

While it is notable that high-level CPUs are precise with their reflexes such as being able to power shield almost all the time to block attacks and reflect projectiles, as well as land attacks that human players would find difficulty landing such as Yoshi's Egg Throw and Pikachu's seemingly perfect control when using Volt Tackle, there are criticisms of each game's AI. There are many complaints surrounding the poor artificial intelligence of computer players in Super Smash Bros. and Super Smash Bros. Melee. YouTube features videos depicting the glitches in this faulty AI system for all three games.

Super Smash Bros.

Examples of flawed AI in Super Smash Bros. (SSB) include:

• Level 9 CPU players which roll incredibly often compared to their later Melee and Super Smash Bros. Brawl counterparts.
• The poor recovery abilities of computer players - e.g., if the player jumps into a level 9 Captain Falcon's up special move, the Captain will not recover. The same thing occurs if the player attacks an opponent's character out of their up special.
• A tendency toward projectile/charge move spamming (such as a level 9 Pikachu consistently using Thunder Jolt or a Donkey Kong level 9 using Giant Punch cancels).
• In Hyrule Castle, a level 9 Kirby may repeatedly use Stone on the left side of the stage, causing him to slide down, resulting in a self-destruct (SD).
• If there is a player on the right side of the Saffron City stage, computer players will walk into the doors of the Pokémon trap due to the item appearing on the hospital building.
• 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.
• When an item appears, a level 9 computer player will attempt to grab it to the point that they will even stop fighting to get the item. However, they will not grab items dropped on clouds in the Yoshi's Island Stage.
• 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 computer player self-destructing.
• A Fox fighting a human player who runs to the edge of a stage such as Dream Land will cause Fox to follow and aim his Fire Fox off of the stage - resulting in a self-destruct.
• A CPU Ness will always aim his PK Thunder as a recovery sideways, even if the ledge is above him.
• A CPU Kirby and Jigglypuff after getting knocked off the stage will immediately use up all their jumps.

Super Smash Bros. Melee

There are several examples of flawed AI in Super Smash Bros. Melee. Most computer players will always spam their neutral attack and projectiles repeatedly (if they are at long distances between the player), and are very easily edge-hogged. Certain stages are notorious for exploiting poor AI, such as Rainbow Cruise and Final Destination. Kongo Jungle is the best known stage for exploiting poor AI as it is easy to KO computer players by simply grabbing an edge, dropping from the edge as they attack, and then re-grabbing the edge. Also, on moving stages such as Icicle Mountain, the computer player will usually move up one platform at a time, which is too slow to escape the lower blast line when the stage speeds up.

The computer players in Melee also make poor use of their shields and use grabs far more often than normal attacks. The best example is Dr. Mario. They also have a tendency to overuse one move, such as Captain Falcon constantly overusing Falcon Dive and Raptor Boost after a forward throw, as well as Ganondorf overusing Dark Dive and a computer controlled Zelda constantly using down tilts. Bowser also spams his Down Attack and Special Down when in the air. Also, most CPU use their basic ground attack often.

Many computer players, especially while metal, will also self-destruct while attempting to meteor smash an opponent. When an item appears, the computer players never pick them up, only picking them up when the player or CPU are next to the items; additionally, they have poor concepts of knowing what items are in front of them, frequently causing them to walk into set Motion-Sensor Bombs or walking Bob-Ombs. Similarly, in Mute City, if they are not on the moving stage's platform, they will not jump onto it if they are not provoked to do so. When there are healing items, Poké Balls, Cloaking Devices, or Hammers present, CPUs will usually immediately cease to fight against the player and will instead flee as to pick up these items. They will often put themselves in harm's way while trying to do so, just to obtain said item.

Specific examples of poor AI include:

• Computer players have generally poor recoveries:
  • They will never attempt to fight off edge guarders.
  • CPU Fox and Falco will always aim 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.
  • 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.
    • Luigi acts as an exception; he will instead always use the Green Missile and never use the Super Jump Punch (even when necessary).
    • Yoshi is also the exception, who will always use his midair jump and never use Egg Roll for recovery.
    • Jigglypuff will always use up all five of its midair jumps to recover; if it can't do so, it will use Sing, guaranteeing a KO.
• 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. Fire Breath also applies; it will never be held past the minimum length.
  • They never use the second hit of Link 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.
  • A CPU Kirby under the effect of Stone will never end the transformation early. Since CPU Kirby never ends the transformation early, he will self destruct on some stages, if he hits a breakable platform or is on a stage thats cause him to slide down to the lower blast line.
  • A CPU Peach rarely ever fastfall after Peach Parasol was used; similarly, CPUs with the Parasol item will never fast-fall with it either. They will never fast fall after being sent flying or jumping either.
• A CPU Jigglypuff never uses Rollout or Rest. Strangely, a Kirby with Jigglypuff absorbed will attempt to use Rollout, but never charge it when using it (as noted above).
• CPU Marth and Roy don't use their Counter move.
• A CPU Ness will only utilize PK Thunder when recovering if they are set to level nine and will always aim same upward diagonal trajectory. A lower level cpu Ness will fall and self destruct if their midair jump is not enough to make it back to the stage. However, a CPU level 9 Ness will self destruct as he will never use PK Thunder after he attacks the player(s) with his aerials while recovering, or hits the ceiling with his midair jump under the stage.
• A high level CPU Mario and Dr. Mario will always jump off the stage and attempt to use their forward aerial to edgeguard against recovering opponents, frequently leading to self destructs; Dr. Maio's attempts at edgeguarding also are poor, as his forward aerial, unlike Mario's, is not a meteor smash. CPU Captain Falcons exhibit similar behavior with their down aerial, but self destruct much less frequently.
  • In Giant Melee, however, it is possible to win a match by not even attacking Captain Falcon if the player faces him in Yoshi's Island. First, the player must jump high enough over the left pit to encourage the CPU Captain Falcon to attempt a down meteor smash, making him get an SD. The player should stand on the central pit (if the blocks are untouched) once Captain Falcon respawns. Then, Captain Falcon usually attempts his neutral aerial attack to hit the player, breaking the blocks and falling, making another SD. After Captain Falcon respawns again, the player should stand near the edges of the central pit. Captain Falcon then jumps from the respawn platform to the left platform. After that, he can attempt another aerial attack that breaks the blocks and make him get another SD. If Captain Falcon manages not to get an SD from falling, then the player can repeat by going to the left side of the stage.
• In Jungle Japes, when battling a level 9 CPU Ness or Roy on one stock, and not moving, the CPU player will try to jump over to the player, but will fall into the river and self destruct. Similar behavior occurs when the player faces a level nine Fox and/or Falco on the stage under slightly different circumstances, and on a level nine Yoshi with one stock on Fourside.
• CPU Kirbys have unusual behavior dealing with their "Inhale" mechanism. When they first use Inhale, they will constantly use it until they can copy a character. Additionally, they will use the move once or twice after taking the ability, but they will never use it again.
• 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. Bowser is an exception to this as he, although rarely, will use his down aerial when the player is above the platform and wields a hammer.
• AI have poor taunting habits. After the CPU respawns, if the player jumps for a distance while the CPU is walking toward him or her, the CPU may eventually taunt for no apparent reason.
  • Upon KOing a character, CPUs will usually taunt, regardless of what is occurring around them.
• 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.
  • Luigi frequently does is Green Missile attack to defend himself in this situation, although he usually fails since the platform he is on is angled upwards.
  • Sometimes the AI will go on the side closer to the Banzai Bill.
  • Also, the AI 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 a CPU Luigi is at the upper blast line without getting KO'd, he will repeatedly use Green Missile until he is out of the upper blast line, which he will then fall straight down until reaching the ground, while making no attempt to dodge or counterattack a pursuing player.
• When a CPU level 9 Ice Climbers is using their grab combined with Blizzard or any throw combines with their down special, they will crouch and stand for few seconds and charge their side smash. While standing for few seconds before they will charge their side smash, they will make no attempt to dodge or counterattack.
• In Rainbow Cruise, when a player is hanging on a ledge on the back side of a flying ship, CPUs will never attack anyone, unless the player is using ledge recovery. Instead CPUs will do nothing, unless an opponent comes near or the healing items, Poké Balls, Cloaking Devices, or Hammers appears.
• If a CPU grabs a Warp Star, they 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, and even self destruct to chase opponents that have jumped off the stage.
• In Hyrule Temple, if a CPU is hit by some attacks that sends them horizontally right powerfully on the right side lower part of the stage, they will recover on the right instead of recovering to the left, resulting in SD.
• Computer players never dash, regardless of level. An exception to this is when an opponent has a hammer, and when the opponent is near, the AI will run straight into the hammer, initially trying to jump over the opponent.
• Upon returning on a Revival platform a computer will immediately enter the fight again regardless of what is happening.
• CPUs will occasionally shield from attacks even when in invincibility frames.
• CPUs will never perform a diagonal aerial dodges, only doing neutral aerial dodges. Thus, it is impossible to see a CPU wavedash.
• During a team battle, CPUs will often stooge on one side of the stage while the opponent is dead. This causes oddities such as constantly turning around when team CPUs are trying to do the same thing. When the opponent falls off their revival platform, the CPU's instantly turn around and walk to them, almost in a robot-like fashion.
• CPUs will only sidestep dodge if they are trying to block a projectile and go through a fall-through platform at the same time. Otherwise, CPUs rely solely on shielding to avoid damage.
• CPUs ignore all items other than the Poke Ball, Cloaking Device, Food, Maxim Tomato, Heart Container, and Hammer. The only time a CPU will grab an item other than those listed is when they're spamming their neutral attack and accidentally pick it up. In the case of one of the listed items appearing and it's far enough away, CPUs will stop fighting their target and attempt to acquire said item.
• In Yoshi's Story, if players stand at the outer edges of the floating platform after the CPUs respawn, the CPUs may simply stand there.
• If they are next to the radius of Venusaur's earthquake or near Wobbuffet, the CPUs may shield even though they are not receiving any blows. This may cause them to break their own shield.
• CPU Peach may get stuck in some walls in Hyrule Temple by continuously attempting to jump. In the lower left part of the stage, the CPU Peach may not be able to go up since right after her second jump, she air dodges.
• If jumping from the leftmost cloud in Yoshi's Island 64, the CPU Mr. Game & Watch may not use his third jump, giving him an SD in most cases.

Super Smash Bros. Brawl

In Super Smash Bros. Brawl, the AI is generally more proficient with character recoveries (most prominently Ness and Luigi's). 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. Another significant change in AI from Melee is that computer players always target human players before other computer players. This behavior can be observed in custom stages that keep the human player out of the computer players' reach, where the computer players will completely ignore each other as they try to reach the human player.

Another new feature is that the computer's level in Training Mode can now be selected. The AI is also 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.

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 more often. This sparked general dislike among the community, many of whom labelled the idea as "cheating". SLAPAHO tested this to see if this were true; no definitive results were returned, however, and they admitted that more experimentation and tests were needed.

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 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.

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. Computer players sometimes have difficulty avoiding certain stage hazards (most notable 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 not as common. And while they are better at recovering than in 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 also tend to play strangely in complex custom stages.

Specific examples of poor AI include:

• When players grab the ledge, computer players will stand still a safe distance from the ledge for some seconds before pursuing the ledge hanging player.
• If a computer player, 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 computer player 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 computer players in Melee could meteor cancel to a moderate degree, computer players 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 (fixed in PAL version).
• CPUs have difficulty recognising walls.
• When a CPU Luigi uses Negative Zone, he will almost always spam Fireball repeatedly, even when set to level nine.
  • Similarly, a CPU Pit using Palutena's Army will spam Palutena's Arrow.
• In the underground version of Mushroomy Kingdom, even a level 9 CPU will sometimes repeatedly attack the blocks, ignoring the player even if items aren't on.
• 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.
• 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 him 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 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 long 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.
• 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.
• 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.
• A CPU Yoshi will never use Egg Throw for recovery.
• A CPU Luigi will never use Luigi Cyclone for recovery.
• Wolf and Fox will Knock themselves out in Sample S: Hole if the player stays still

External links

• http://www.youtube.com/watch?v=rk_EhpxKu8Q - Abusing DK's AI in training mode
• http://www.youtube.com/watch?v=71yUbTsR54E&feature=related - The majority of TAS videos by Andtgar show off abusing SSB AI while perfectly comboing.