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

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 Falcon 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 at least one self-destruct, and possibly more.
• A CPU Ness will always aim his 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/Ride 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 grab attacks 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 forward throw, as well as Ganondorf overusing Dark Dive and a computer controlled Zelda constantly using the strong down attack. 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 (except healing items, Poké Balls, Cloaking Devices, or Hammers); instead, they only pick them up when the player or CPU are next to the items.

Specific examples of poor AI include:

• Computer players when recovering, will never fight back to fend off an edge guarder.
• Computer players will never utilise alternative recovery methods of any character when recovering.
• Computer players never charge their smash attacks. Likewise, a cpu Marth, Roy, and Kirby who absorbed one of the two previous characters will never charge their neutral special when they use it.
• A CPU Luigi will never use Super Jump Punch. This is especially problematic during recovery, as even if he is directly below a ledge, he will not use it. Instead he will always use his Green Missile, which gains very little vertical distance.
• Computer players never use counter special moves such as Peach's Toad, and Marth's and Roy's Counter.
• A CPU Bowser and Kirby with Bowser absorbed will never use Fire Breath past the minimum holding time.
• 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.
• A CPU Ness will only utilise PK Thunder when recovering if they are set to level nine. 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 will never use their wall-grapple to recover.
• A high level CPU Mario and Dr. Mario will always jump off the stage and attempt to use their fair to edgeguard against recovering opponents. Depending the stage, this can often lead to self destructs. CPU Captain Falcons exhibit similar behavior with their dair, but self destruct much less frequently.
• In Jungle Japes, when battling a level nine Ness on one stock, and not moving, Ness 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 none Yoshi with one stock on Fourside.

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

There has been speculation that the AI at level 9 reads button commands and reacts accordingly, which allows them to perfect shield so often. This has sparked anger among some smashers who feel that the AI should be made better rather than do what they term as "cheating". Some inconclusive experiments were performed by the SLAPAHO crew to see if this allegation is true, and though no definitive results were obtained, their findings justify future experimentation and research. However, many smashers (mostly experienced) conclude that regardless, the AI at level 9 is still easy to beat because of their heavily exploitable flaws (and they even go as far as joking about their "difficulty" by recording occasions where they perform feats otherwise impossible for the AI to do

There also appears to be a system in place which enables the AI to learn. 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 fewer, but still 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 Ride 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 on a stage with platforms above the main 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 percents than they KO human players.
• 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 (though these were supposedly fixed for the PAL release of the game).
• 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.

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.