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'''Artificial intelligence''', abbreviated as '''AI''',  in the [[Super Smash Bros. (series)|''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 Mode]]s. 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.
{{redirect|CPU|the California smasher|Smasher:CPU}}{{for|the Florida smasher|Smasher:CPU (Florida)}}{{for|the Japanese smasher|Smasher:CPU1 (Japan)}}
[[File:CPUSmashU.png|thumb|A computer player in {{forwiiu}}, along with its selectable levels.]]


Artificial intelligence levels range from 1-9, with 1 being the weakest and 9 the strongest. Certain [[event]]s in ''Melee'' give opponents a level of 0, which results in them not attacking at all (but still following whatever movement behaviour they would normally have).
'''Artificial intelligence''', abbreviated as '''AI''', in the ''{{b|Super Smash Bros.|series}}'' series refers to the intelligence of any computer-controlled ('''CP''' in ''[[Super Smash Bros.]]'' and ''[[Super Smash Bros. Melee]]'', '''CPU''' from ''[[Super Smash Bros. Brawl]]'' onward) character (called '''computer players''' in-game) in the [[Single Player modes|single-player]] and [[Versus Mode]]s. 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.


==Training against CPUs==
==Difficulty levels==
Players commonly fight against CPUs to train when there aren't other players around to play. This is a practise that is criticised 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 [[mindgames|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.
Artificial intelligence levels range from 1 to 9, with 1 being the weakest and 9 being the strongest. The default CPU level in Versus matches is 1 for ''Melee'' and 3 in all other games, although rule settings in ''[[Super Smash Bros. Ultimate]]'' allow players to select which level CPUs default to. 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, waiting for a long time before eventually doing it, while the level 9 almost always will instantly. Likewise, lower level CPUs are unlikely to [[shield]] or [[dodge]] an attack, using [[roll]]s simply to reposition themselves in some instances, and almost never using their [[shield]] at all, or at random times in ''Brawl''. On the other hand, higher-level ones almost always defend from attacks, generally having good reflexes or dodging any attack when not in lag - in all games, level 9 CPUs are able to perfectly land attacks against opponents when at the appropriate range from them, and in ''Brawl'', ''[[Super Smash Bros. 4]]'', and ''Ultimate'', they can defend against almost any attack with one-frame reactions, resulting in disproportionate [[perfect shield]]ing and [[dodging]] capabilities. [https://www.ssbwiki.com/Button_mashing Button Mashing] also changes between CPUs like waking up from a [https://www.ssbwiki.com/Sleep Sleep] or recovering after a [https://www.ssbwiki.com/Shield#Shield_breaking] Shield Break. Low level CPUS mashing at a very slow speed with higher CPUS mashing at a very fast speed (with level 9s having frame-perfect mashing speed). Also due to this change in reflexes, low-level CPUs are prone to simply standing next to their opponent and using a weak attack such as a [[neutral attack]] or [[tilt]], while high-level CPUs use [[aerial attack]]s, [[smash attack]]s, and [[grab]]s more prominently.


However, training against CPUs does have its merits. CPUs can be used to effectively practise [[combo]]s and [[chain throw]]s, as well as [[spacing]], [[punish]]ing 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 want to practise the aforementioned things. Many top professional smashers have reported using CPUs to train, such as {{Sm|Nairo}} and {{Sm|Vinnie}}.
The AI's [[recovery]] also improves as their level is increased: CPUs at low levels tend to recover in a simple and predictable pattern with their [[up special]]s, or may not use them at all in ''SSB'', while high-level ones in ''Brawl'', ''Smash 4'', and ''Ultimate'' are capable of properly combining or alternating between different recovery techniques. For example, CPU {{SSB4|Luigi}} in ''Smash 4'' only uses his [[Super Jump Punch]] to recover at low levels (specifically Level 1 to 5), while at high levels (6-9) he also makes use of his [[Green Missile]] and [[Luigi Cyclone]].


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 practise.
In [[Training mode]], besides attacking, CPUs also have many other "[[List of CPU modes|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 ''SSB'' and ''Melee'', these are set to a predetermined level (levels 3 and 1 respectively), while in ''Brawl'', ''Smash 4'', and ''Ultimate'', 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 [[gimp]]able pattern, while level 9 ones will almost always air dodge after [[tumbling]] (in ''Brawl'') and will choose better recovery options. When set to Attack, CPUs will fight the player as on usual battles, but since the level cannot be selected in ''SSB'' and ''Melee'', it is somewhat unfavorable to fight CPUs on Training mode. Players instead tend to train against them on normal Versus modes. CPUs set to Attack mode in ''Smash 4''{{'}}s Training mode are also much likelier to [[spam]] projectiles and other special moves than in other modes, using them even at close range from opponents.


==Flaws in the AI==
Certain single-player stages and [[event]]s in ''Melee'' give CPUs a level of 0, such as [[Event 19: Peach's Peril]] and [[Event 21: Ice Breaker]], in which case they don't attack at all, but still follow whatever movement behavior they would normally have. Some also give them other specific behaviors, such as [[Event 3: Bomb-fest]] in ''Melee'' causing CPU {{SSBM|Link}} and {{SSBM|Samus}} to use their [[down special]] moves more often, and [[Event 31: The Ultimate Bodyguard]] in ''Brawl'' causing CPU {{SSBB|Zelda}} to [[crouch]] and do nothing until the stage changes a second time. In ''Melee'', these specific behaviors can be accessed via the {{SSBM|Debug Menu}}.
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, 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 is can be extremely flawed in most scenarios. 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]]'' 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.]]''===
In ''SSB'', CPU levels appear on the [[character selection screen]] as a digit with two arrows on either side to adjust it up or down, appearing where the selected character's name would be displayed for a human. In ''Melee'', the levels are instead adjusted with a red slider which can be selected with the [[A button]] and then moved with the [[control stick]], which increases in number from left to right, above the selected CPU character's name. In ''Brawl'', ''Smash 4'', and ''Ultimate'', only the level number to which the CPU is currently set is shown at first, now appearing where the option to choose a [[name]] would appear for human players; clicking the number displays a menu with the other levels, scrolled by moving the cursor up and down. In ''Smash 4'' and ''Ultimate'', the numbers appear with colors changing from indigo to red as the level increases, while in ''Brawl'', all numbers appear in black but with an adjective to accompany each CPU level and describe its skill, namely '''Puny''', '''Wimpy''', '''Weak''', '''Normal''', '''Hardy''', '''Strong''', '''Burly''', '''Mighty''', and '''Nasty''' in ascending order.
<!-- READ THE FOLLOWING GUIDELINES BEFORE ADDING ANY EXAMPLES:
1. Avoid adding very specific, situational instances that rarely, if ever, show up, where a computer player may not perform optimally. If you have to specify what level the CPU is, the character, the stage, what the CPU is attempting, and even the exact location on the stage, do not add it. Also do not add examples that require nonstandard gameplay, and do not add examples that you have to write a small guide to replicate.
2. Suboptimal play by the CPU in general does not constitute an AI flaw. For something to be considered an AI flaw, it has to be a repeated behavior by the AI that directly hinders a CPU's performance regardless of outside circumstances.
3. Per the previous guideline, a potential example must be a behavior by the CPU that it will nearly always repeat when the circumstances leading to the example occurs.
4. Examples are ordered, so when putting down an example, make sure it fits the order. The order goes; general flaws > character specific flaws > item related flaws > stage related flaws > character + specific stage flaw.-->


Examples of flawed AI in ''Super Smash Bros.'' (''SSB'') include:
The [[amiibo]] figures released for ''Super Smash Bros. 4'' and ''Super Smash Bros. Ultimate'' have stored data for a CPU fighter within them. The player may [[character customization|customize]] said character and train them by having them battle. The amiibo is labeled with "FP", and can gain experience to level up after the battle, capping at level 50. Battling amiibo against each other will yield more experience than battling a human or regular CPU. Additionally, amiibo will "learn" from repeated battles by changing its tactics in response to its opponents' behavior (e.g. if the amiibo battles an opponent that shields frequently, it will learn to use its own shield more effectively and counter shielding opponents with grabs).
*Level 9 CPU players which [[roll]] incredibly often compared to their later ''Melee'' and ''[[Super Smash Bros. Brawl]]'' counterparts.
*The general poor [[recovery]] abilities of CPUs - e.g., if the player jumps into a level 9 [[Captain Falcon (SSB)|Captain Falcon's]] [[Falcon Dive]], he will not attempt to recover. The same thing occurs if the player attacks any CPU character out of their [[up special]].
**A CPU {{SSB|Ness}} will always aim his [[PK Thunder]] as a recovery sideways, even if the ledge is above him.
**A CPU Kirby and {{SSB|Jigglypuff}} after getting knocked off the stage will immediately use up all their jumps.
*A tendency toward [[projectile]]/charge move [[spam]]ming (such as a level 9 {{SSB|Pikachu}} consistently using [[Thunder Jolt]] or a level 9 {{SSB|Donkey Kong}} using [[Giant Punch]] cancels).
*When an [[item]] appears, a level 9 CPU will cease all fighting to get the item. However, they will ignore items dropped on clouds in the {{SSB|Yoshi's Island}}.
*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.
*In [[Hyrule Castle]], a level 9 {{SSB|Kirby}} may repeatedly use [[Stone]] on the left side of the stage, causing him to slide down, resulting in a [[self-destruct]].
*If there is a player on the right side of the [[Saffron City]] stage, CPUs will walk into the doors of the Pokémon trap.
*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.
*A {{SSB|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.<ref>{{cite web| url = http://www.youtube.com/watch?v=OGPMxhH5Zss | title = Super Smash Bros 64 - Tricking Fox's AI | accessmonthday = Jan 2| accessyear = 2011| author = [http://www.youtube.com/user/JetlagJad JetlagJad]| date = 2007-05-23| format = video| work = | publisher = YouTube| quote = }}</ref>


===''[[Super Smash Bros. Melee]]''===
==Training against CPUs==
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-hog]]ged. Certain stages are notorious for exploiting poor AI, such as [[Rainbow Cruise]] and {{SSBM|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.
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 of skill 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 [[mindgames|mind gaming]], or even learning from their mistakes and changing their tactics accordingly.


The computer players in ''Melee'' also make poor use of their [[shield]]s and use [[grab]]s far more often than normal attacks. Despite minimal use of their shields, CPUs are very precise with [[power shield]]ing to both block attacks and reflect projectiles; CPU's will almost always perfect-shield a projectile. They also have a tendency to overuse one move, such as {{SSBM|Captain Falcon}} repeatedly using Falcon Dive and [[Raptor Boost]] after a [[forward throw]], as well as {{SSBM|Ganondorf}} overusing [[Dark Dive]] when a character is in front of and above him, and {{SSBM|Zelda}} constantly using her [[down tilt]] to "lock" opponents.
Training against CPUs is said to not adequately build one's skills beyond basic offense and defense (such as the ability to read and bait opponents), and it is often argued that excessive CPU training may cause a player to actually become slightly worse by developing habits that only work against CPUs and will be heavily exploited by human players. For example, if a Marth player uses [[Counter]] every time a CPU gets close to attack, it would fall for it most of the time (especially higher-level CPUs), without trying to bait the counter or use grabs more often. However, a skilled or even a remotely competent human player would quickly catch onto the Marth player's strategy and exploit it by feigning an attack in the cases where Marth would commonly use Counter, and then punish him with a grab or delayed powerful attack such as a charged smash. Another example is CPUs not avoiding or fighting off edge-guarders effectively in the first three ''Smash'' games, which allows players to KO them with basic edgeguarding techniques, while experienced players would prevent this at all costs. Also in ''Smash 4'' and ''Ultimate'', higher-level CPU's (mostly levels 7-9) also have next to frame-perfect aerial dodging, only doing so when a player or CPU inputs the attack near them, or when items such as projectiles end up close enough to them. As a result, high-level CPUs in the air can only effectively be hit by rapid-hitting moves or through true combos. This can make practicing aerial combos infuriating, especially with characters who rely heavily on their aerial games, such as Marth, Peach, and Jigglypuff; this is further accentuated by their constant hold of the jump command while in the air (even when out of jumps), as they will, more often than not, [[Footstool Jump|phantom footstool]] the player, leaving the CPU in a favorable situation away from the player.


Many computer players, especially while [[Metal Box|metal]], will also self-destruct while attempting to [[meteor smash]] an opponent. When an item appears, CPUs will never pick them up, only picking them up accidentally 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. There is an exception to this when there are healing items, Poké Balls, [[Cloaking Device]]s, or [[Hammer]]s 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.
However, training against CPUs does have its merits. CPUs can be used to effectively practice [[combo]]s and [[chain throw]]s, as well as [[spacing]], [[punish]]ing, 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 {{Sm|Nairo}}, {{Sm|Vinnie}}, and {{Sm|Mew2King}}.


<!-- READ THE FOLLOWING GUIDELINES BEFORE ADDING ANY EXAMPLES:
There is, however, no consensus as to which 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. Other players say Level 6-8 CPUs are the best for being challenging but not having inhuman reactions at the same time. Another camp maintains that what level is best is dependent on what a player is trying to practice.
1. Avoid adding very specific, situational instances that rarely, if ever, show up, where a computer player may not perform optimally. If you have to specify what level the CPU is, the character, the stage, what the CPU is attempting, and even the exact location on the stage, do not add it. Also do not add examples that require nonstandard gameplay, and do not add examples that you have to write a small guide to replicate.
2. Suboptimal play by the CPU in general does not constitute an AI flaw. For something to be considered an AI flaw, it has to be a repeated behavior by the AI that directly hinders a CPU's performance regardless of outside circumstances.
3. Per the previous guideline, a potential example must be a behavior by the CPU that it will nearly always repeat when the circumstances leading to the example occurs.  
4. Examples are ordered, so when putting down an example, make sure it fits the order. The order goes; general flaws > character specific flaws > item related flaws > stage related flaws > character + specific stage flaw.-->


Specific examples of poor AI include:
==Flaws in the AI==
*Computer players have generally poor recovery abilities:
{{main|Flaws in artificial intelligence}}
**They will never attempt to fight off 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 dodge]]s or [[wall-grapple]]s.
***{{SSBM|Luigi}} acts as an exception; he will instead always use the [[Green Missile]] and never use [[Super Jump Punch]] to recover (even when necessary).
**CPU {{SSBM|Fox}} and {{SSBM|Falco}} 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 {{SSBM|Jigglypuff}} runs out of midair jumps when recovering, it will use [[Sing]], guaranteeing a failed recovery.
**A CPU {{SSBM|Ness}} will only utilise [[PK Thunder]] when recovering if they are set to level nine, and will always aim it in the 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.
*Computer players have poor concept of continuous attacks:
**They never charge attacks that require button holding, including: [[smash attack]]s (with the exception of the {{SSBM|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 {{SSBM|Link}}'s or {{SSBM|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. 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.
*CPUs will never initiate a [[fast fall]].
*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.
*CPUs will never initiate a [[dash]] outside [[dash grab]]s.
*Upon returning on a [[Revival platform]], CPUs will immediately reenter the fight again regardless of what is happening.
*CPUs will still shield attacks when [[invincible]].
*When air dodging, CPUs will never utilise the ability to air dodge towards a direction.
*CPUs will never [[sidestep]] intentionally; the only time they will sidestep is when they are trying to both shield and fall through a soft platform.
*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).
*A CPU {{SSBM|Marth}} and {{SSBM|Roy}} will never use [[Counter]]. Similarly, a CPU {{SSBM|Peach}} will never use [[Toad (move)|Toad]] (though like with Jigglypuff and Rollout, a Kirby with Peach absorbed will use it).
*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 use the move once or twice after taking the ability, but they will never use it again.
*A high level CPU {{SSBM|Mario}} and {{SSBM|Dr. Mario}} will often jump off the stage and attempt to use their [[forward aerial]] to edgeguard against recovering opponents, which depending on the stage, frequently leads to self destructs. CPU Captain Falcons exhibit similar behavior with their [[down aerial]], but rarely self destruct when they do so.
*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.
*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. They will also jump offstage to chase opponents that have jumped off the stage, and self destruct in the process.
*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 Pokemon's damage radius.
*When the player stands still on the absolute ledge of certain platforms, 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 {{SSBM|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 battling a level 9 CPU Ness or Roy one on one, and the player does not move, the CPU will try to jump over to the player, but will fall into the river and self destruct their first stock. Similar behavior occurs when the player faces a level nine Fox or Falco on the stage under slightly different circumstances, and on a level nine {{SSBM|Yoshi}} on [[Fourside]].
 
===''[[Super Smash Bros. Brawl]]''===
In ''Super Smash Bros. Brawl'', the AI is generally more proficient with character recoveries (most prominently {{SSBB|Luigi}}). If a human player gets an [[item]] like a [[Starman (item)|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 have a preference to targeting human players before other computer players.
 
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:
#Puny-1
#Wimpy-2
#Weak-3 (the default level)
#Normal-4
#Hardy-5
#Strong-6
#Burly-7
#Mighty-8
#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.<ref name="CECPUexpBlog">{{cite web| url = http://allisbrawl.com/blogpost.aspx?id=8848| title = The Wonders of Brawl's CPU Experience System| accessmonthday = Jan 2| accessyear = 2011| author = [http://allisbrawl.com/blog.aspx?id=10347 ChurroEmiliano]| date = 2008-12-31| format = blogpost| work = | publisher = [http://allisbrawl.com/ AllIsBrawl.com]| quote = When developing Super Smash Bros. Brawl, Sakurai integrated an experience system in which CPUs (mostly level 9/nasty) would actually learn from other players and try to mimic such strategies.  This experience system is subject to all characters. / The way you and others play on your save data, the way they will intend to play, keeping several of their own ways of playing as well. You can tell a huge difference, by comparing...a new fresh save data of Brawl, to a very much used save data.}}</ref><ref name="CECPUexpVideo">{{cite web
| url = http://www.youtube.com/watch?v=g4HvhIPOz4I| title = The Wonders of Brawl's CPU Experience System| accessmonthday = Jan 2| accessyear = 2011| author = [http://www.youtube.com/user/ChurroEmiliano ChurroEmiliano]| date = 2008-12-29| format = video| work = | publisher = YouTube| quote = Churro (Snake) vs. Lvl 9 Link}}</ref><ref name="CEFalconPunch">{{cite web
| url = http://www.youtube.com/watch?v=YMcEUsMd9Cw| title = Falcon Punch Much? 0_0| accessmonthday = Jan 2| accessyear = 2011| author = [http://www.youtube.com/user/ChurroEmiliano ChurroEmiliano]| date = 2008-12-31| format = video | work = | publisher = YouTube| quote = After having several Falcon Punch free-for-alls, the CPU wanted to fit in.
}}</ref> [[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,<ref name="jerkette">{{cite web| url = http://www.youtube.com/watch?v=diJX703iC0A| title = ...jerkette| accessmonthday = Jan 2| accessyear = 2011| author = [http://www.youtube.com/user/Hoidsa Hoidsa]| date = 2009-05-13| format = video| work = | publisher = YouTube| quote = }}</ref> and to overuse Falcon Punches after humans play several Falcon Punch free-for-alls.<ref name="CEFalconPunch" /> 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 notable on [[Halberd]]), and are prone to self destructing in scrolling stages, such as the [[Past and Melee Stages|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 [[edge sweet spot|sweetspotted]] when recovering, even when there are "soft" platforms off the stage.
==Learning AI and reading inputs myths==
While still suffering flaws like ''Smash 64'' and ''Melee'', CPUs within ''Brawl'' came under scrutiny by members of the ''Brawl'' community after analyzing the behavior of them within fights. Two primary theories surrounding the AI eventually became commonplace:


Computer players also tend to play strangely in complex custom stages.
#That the CPU was able to read inputs from human players and thus have perfect reaction times, explaining the excessive propensity of a CPU to [[perfect shield]].
#That a "learning system" existed within ''Brawl's'' code that allowed computer players to slowly learn to adapt to human players.


Aside from being flawed as stated above, in [[Free-for-all]]s, CPUs will target the human player even if they aren't [[team]]ed. 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.
The former rumor was especially controversial, as many smashers thought that allowing the AI to "cheat" was an unfair tactic, and such a programming decision was considered lazy. The American crew [[SLAPAHO]] attempted to see whether or not CPUs had perfect reaction times, but their results were eventually declared inconclusive, and more tests were intended to be carried out; inactivity by the group, however, caused these further tests to never occur. In 2013, Canadian smasher {{Sm|Toomai}} analyzed [[Talk:Artificial intelligence#The latest claimed AI cheating proof|various animated GIFs of CPUs]] responding to aerial attacks; it was ultimately demonstrated that CPUs had a reaction time of one frame, and thus, did not read button inputs to form decisions.


Specific examples of poor AI include:
The second rumor was primarily spread by an [[All is Brawl]] blog post by American smasher Churro; entitled "The Wonders of Brawl's CPU Experience System", Churro claimed that CPUs in ''Brawl'' could learn from human players, with such changes being unique from different save files for ''Brawl''. Churro provided video examples of these supposed changes, such as how a CPU {{SSBB|Captain Falcon}} began to more frequently use [[Falcon Punch]] following an all-Captain Falcon match featuring overuse of the move. Other videos by other smashers also appeared to show CPUs using tactics such as [[dash dancing]] and [[DACUS]]es.
<!-- READ THE FOLLOWING GUIDELINES BEFORE ADDING ANY EXAMPLES:
1. Avoid adding very specific, situational instances that rarely, if ever, show up, where a computer player may not perform optimally. If you have to specify what level the CPU is, the character, the stage, what the CPU is attempting, and even the exact location on the stage, do not add it. Also do not add examples that require nonstandard gameplay, and do not add examples that you have to write a small guide to replicate.
2. Suboptimal play by the CPU in general does not constitute an AI flaw. For something to be considered an AI flaw, it has to be a repeated behavior by the AI that directly hinders a CPU's performance regardless of outside circumstances.
3. Per the previous guideline, a potential example must be a behavior by the CPU that it will nearly always repeat when the circumstances leading to the example occurs.  
4. Examples are ordered, so when putting down an example, make sure it fits the order. The order goes; general flaws > character specific flaws > item related flaws > stage related flaws > character + specific stage flaw.-->


*CPUs still underutilise the recoveries of several characters:
Initially widely believed, advances in the hacking scene for ''Brawl'' have since disproven the existence of a learning system for CPUs:
**A CPU {{SSBB|Ness}} and {{SSBB|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 {{SSBB|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.
*Tests showed that there were no differences in CPU behavior from save files that were over several hundred hours old versus fresh save files; comparisons of two files with significant playtime also showed no differences, when such a case was supposed to have significantly different playstyles.
**A CPU {{SSBB|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.
*Disassembling [[Replay]] files showed that no CPU inputs are saved in the file, only human inputs; as such, this meant that whenever a replay was played back, it meant that the CPU would have to react the same way every time in order to prevent desyncing. A learning system could potentially cause CPUs to react differently in replays, thus further disproving the rumor.
**A CPU {{SSBB|Yoshi}} will never use Egg Throw for recovery.
*Disassembling the ''Brawl'' save file showed that there were no flags or other notes about the AI.
**A CPU Luigi will never use [[Luigi Cyclone]] for recovery.
*Disassembly of the game's AI demonstrated no coding for learning from human players.
**A CPU {{SSBB|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.
*Videos demonstrating that the AI could learn are thought to have suffered from {{s|wikipedia|confirmation bias}}; what were thought to be cases of the AI learning were cases of the AI performing as expected, including specific overuse of some attacks.
**A CPU {{SSBB|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 into a {{SSBB|Fox}} or {{SSBB|Falco}} using their up specials during the charge up phase of their move, they will angle the recovery horizontally and self-destruct.
**If a CPU {{SSBB|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.
*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.<ref>http://www.youtube.com/watch?v=D9nursdpKIw</ref>
*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.
*CPUs have [http://www.youtube.com/watch?v=qryrf87N5OQ difficulty recognising walls].
*When {{SSBB|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.
*When {{SSBB|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.
*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]], CPUs will sometimes repeatedly attack the blocks, ignoring the player even if items aren't on.


==External links==
A rudimentary learning system similar to the above would eventually be used by [[amiibo]] in ''Super Smash Bros. 4'' and ''Super Smash Bros. Ultimate'', though no such learning system exists outside of this.
*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.
*[http://youtube.com/watch?feature=related&v=EZwg37tu6B0 A video showing an AI flaw of Falco in ''Melee'']


==References==
==See also==
<references/>
*[[Amiibo]]


[[Category:Gameplay]]
[[Category:Gameplay]]

Latest revision as of 08:02, September 6, 2024

"CPU" redirects here. For the California smasher, see Smasher:CPU.
For the Florida smasher, see Smasher:CPU (Florida).
For the Japanese smasher, see Smasher:CPU1 (Japan).
A computer player in Super Smash Bros. for Wii U, along with its selectable levels.

Artificial intelligence, abbreviated as AI, in the Super Smash Bros. series refers to the intelligence of any computer-controlled (CP in Super Smash Bros. and Super Smash Bros. Melee, CPU from Super Smash Bros. Brawl onward) 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[edit]

Artificial intelligence levels range from 1 to 9, with 1 being the weakest and 9 being the strongest. The default CPU level in Versus matches is 1 for Melee and 3 in all other games, although rule settings in Super Smash Bros. Ultimate allow players to select which level CPUs default to. 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, waiting for a long time before eventually doing it, while the level 9 almost always will instantly. Likewise, lower level CPUs are unlikely to shield or dodge an attack, using rolls simply to reposition themselves in some instances, and almost never using their shield at all, or at random times in Brawl. On the other hand, higher-level ones almost always defend from attacks, generally having good reflexes or dodging any attack when not in lag - in all games, level 9 CPUs are able to perfectly land attacks against opponents when at the appropriate range from them, and in Brawl, Super Smash Bros. 4, and Ultimate, they can defend against almost any attack with one-frame reactions, resulting in disproportionate perfect shielding and dodging capabilities. Button Mashing also changes between CPUs like waking up from a Sleep or recovering after a [1] Shield Break. Low level CPUS mashing at a very slow speed with higher CPUS mashing at a very fast speed (with level 9s having frame-perfect mashing speed). Also due to this change in reflexes, low-level CPUs are prone to simply standing next to their opponent and using a weak attack such as a neutral attack or tilt, while high-level CPUs use aerial attacks, smash attacks, and grabs more prominently.

The AI's recovery also improves as their level is increased: 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 SSB, while high-level ones in Brawl, Smash 4, and Ultimate are capable of properly combining or alternating between different recovery techniques. For example, CPU Luigi in Smash 4 only uses his Super Jump Punch to recover at low levels (specifically Level 1 to 5), while at high levels (6-9) he also makes use of his Green Missile and Luigi Cyclone.

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 SSB and Melee, these are set to a predetermined level (levels 3 and 1 respectively), while in Brawl, Smash 4, and Ultimate, 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 (in Brawl) and will choose better recovery options. When set to Attack, CPUs will fight the player as on usual battles, but since the level cannot be selected in SSB and Melee, it is somewhat unfavorable to fight CPUs on Training mode. Players instead tend to train against them on normal Versus modes. CPUs set to Attack mode in Smash 4's Training mode are also much likelier to spam projectiles and other special moves than in other modes, using them even at close range from opponents.

Certain single-player stages and events in Melee give CPUs a level of 0, such as Event 19: Peach's Peril and Event 21: Ice Breaker, in which case they don't attack at all, but still follow whatever movement behavior they would normally have. Some also give them other specific behaviors, such as Event 3: Bomb-fest in Melee causing CPU Link and Samus to use their down special moves more often, and Event 31: The Ultimate Bodyguard in Brawl causing CPU Zelda to crouch and do nothing until the stage changes a second time. In Melee, these specific behaviors can be accessed via the Debug Menu.

In SSB, CPU levels appear on the character selection screen as a digit with two arrows on either side to adjust it up or down, appearing where the selected character's name would be displayed for a human. In Melee, the levels are instead adjusted with a red slider which can be selected with the A button and then moved with the control stick, which increases in number from left to right, above the selected CPU character's name. In Brawl, Smash 4, and Ultimate, only the level number to which the CPU is currently set is shown at first, now appearing where the option to choose a name would appear for human players; clicking the number displays a menu with the other levels, scrolled by moving the cursor up and down. In Smash 4 and Ultimate, the numbers appear with colors changing from indigo to red as the level increases, while in Brawl, all numbers appear in black but with an adjective to accompany each CPU level and describe its skill, namely Puny, Wimpy, Weak, Normal, Hardy, Strong, Burly, Mighty, and Nasty in ascending order.

The amiibo figures released for Super Smash Bros. 4 and Super Smash Bros. Ultimate have stored data for a CPU fighter within them. The player may customize said character and train them by having them battle. The amiibo is labeled with "FP", and can gain experience to level up after the battle, capping at level 50. Battling amiibo against each other will yield more experience than battling a human or regular CPU. Additionally, amiibo will "learn" from repeated battles by changing its tactics in response to its opponents' behavior (e.g. if the amiibo battles an opponent that shields frequently, it will learn to use its own shield more effectively and counter shielding opponents with grabs).

Training against CPUs[edit]

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 of skill 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, or even learning from their mistakes and changing their tactics accordingly.

Training against CPUs is said to not adequately build one's skills beyond basic offense and defense (such as the ability to read and bait opponents), and it is often argued that excessive CPU training may cause a player to actually become slightly worse by developing habits that only work against CPUs and will be heavily exploited by human players. For example, if a Marth player uses Counter every time a CPU gets close to attack, it would fall for it most of the time (especially higher-level CPUs), without trying to bait the counter or use grabs more often. However, a skilled or even a remotely competent human player would quickly catch onto the Marth player's strategy and exploit it by feigning an attack in the cases where Marth would commonly use Counter, and then punish him with a grab or delayed powerful attack such as a charged smash. Another example is CPUs not avoiding or fighting off edge-guarders effectively in the first three Smash games, which allows players to KO them with basic edgeguarding techniques, while experienced players would prevent this at all costs. Also in Smash 4 and Ultimate, higher-level CPU's (mostly levels 7-9) also have next to frame-perfect aerial dodging, only doing so when a player or CPU inputs the attack near them, or when items such as projectiles end up close enough to them. As a result, high-level CPUs in the air can only effectively be hit by rapid-hitting moves or through true combos. This can make practicing aerial combos infuriating, especially with characters who rely heavily on their aerial games, such as Marth, Peach, and Jigglypuff; this is further accentuated by their constant hold of the jump command while in the air (even when out of jumps), as they will, more often than not, phantom footstool the player, leaving the CPU in a favorable situation away from the player.

However, training against CPUs does have its merits. CPUs can be used to effectively practice combos and chain throws, as well as spacing, punishing, 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, Vinnie, and Mew2King.

There is, however, no consensus as to which 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. Other players say Level 6-8 CPUs are the best for being challenging but not having inhuman reactions at the same time. Another camp maintains that what level is best is dependent on what a player is trying to practice.

Flaws in the AI[edit]

Main article: Flaws in artificial intelligence

Learning AI and reading inputs myths[edit]

While still suffering flaws like Smash 64 and Melee, CPUs within Brawl came under scrutiny by members of the Brawl community after analyzing the behavior of them within fights. Two primary theories surrounding the AI eventually became commonplace:

  1. That the CPU was able to read inputs from human players and thus have perfect reaction times, explaining the excessive propensity of a CPU to perfect shield.
  2. That a "learning system" existed within Brawl's code that allowed computer players to slowly learn to adapt to human players.

The former rumor was especially controversial, as many smashers thought that allowing the AI to "cheat" was an unfair tactic, and such a programming decision was considered lazy. The American crew SLAPAHO attempted to see whether or not CPUs had perfect reaction times, but their results were eventually declared inconclusive, and more tests were intended to be carried out; inactivity by the group, however, caused these further tests to never occur. In 2013, Canadian smasher Toomai analyzed various animated GIFs of CPUs responding to aerial attacks; it was ultimately demonstrated that CPUs had a reaction time of one frame, and thus, did not read button inputs to form decisions.

The second rumor was primarily spread by an All is Brawl blog post by American smasher Churro; entitled "The Wonders of Brawl's CPU Experience System", Churro claimed that CPUs in Brawl could learn from human players, with such changes being unique from different save files for Brawl. Churro provided video examples of these supposed changes, such as how a CPU Captain Falcon began to more frequently use Falcon Punch following an all-Captain Falcon match featuring overuse of the move. Other videos by other smashers also appeared to show CPUs using tactics such as dash dancing and DACUSes.

Initially widely believed, advances in the hacking scene for Brawl have since disproven the existence of a learning system for CPUs:

  • Tests showed that there were no differences in CPU behavior from save files that were over several hundred hours old versus fresh save files; comparisons of two files with significant playtime also showed no differences, when such a case was supposed to have significantly different playstyles.
  • Disassembling Replay files showed that no CPU inputs are saved in the file, only human inputs; as such, this meant that whenever a replay was played back, it meant that the CPU would have to react the same way every time in order to prevent desyncing. A learning system could potentially cause CPUs to react differently in replays, thus further disproving the rumor.
  • Disassembling the Brawl save file showed that there were no flags or other notes about the AI.
  • Disassembly of the game's AI demonstrated no coding for learning from human players.
  • Videos demonstrating that the AI could learn are thought to have suffered from confirmation bias; what were thought to be cases of the AI learning were cases of the AI performing as expected, including specific overuse of some attacks.

A rudimentary learning system similar to the above would eventually be used by amiibo in Super Smash Bros. 4 and Super Smash Bros. Ultimate, though no such learning system exists outside of this.

See also[edit]

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