AI Breaker: Difference between revisions

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Either the programmers didn't consider the possibility of the player doing this, couldn't come up with an effective counter or there's a bug in the system that makes it perform in ways not intended.

Ultimately, even if the AI does always respond in the "best possible" way to an action, it may still become an AI Breaker - by making the opponent(s) too predictable. The most common exploits are:

Ultimately, even if the AI does always respond in the "best possible" way to an action, it may still become an AI Breaker - by making the opponent(s) too predictable. Which means it loses in [[Metagame]], if it can't adapt. Once you figure out how to create situations where its optimization becomes a disadvantage, and the more its strategy is focused and immutable, the greater is its disadvantage against specialized counter-moves. The most common exploits are:

* "Strong Defender + Strong Attacker": An unit continues to attack whichever enemy it saw first / reached first / was attacked by first? You give it [[Stone Wall|something with greatest possible defence value]] to scratch and follow with [[Glass Cannon]]s right on its heels.

* AI units chase whoever they see on their own, without any coordination with allies? [[Fishing for Mooks|Kiting]], plus ambush if possible.

* AI constantly chooses the "best" path? If you can make one or another "more optimal", it will waver between the paths, never arriving anywhere. So you make it shuffle back and forth where it can't reach you but is whittled down by long-range weapons, traps or dangerous terrain.

* Priorities are not weighted reasonably close and against other factors, but are overriding? Show it the cheese it wants, build mousetraps on the way there.

* The game cut corners with a combination of [[The All-Seeing AI]] and straightforward algorithms? The downside: if the enemies had [[Fog of War]], most of the time you could not be sure what exactly ''they'' did see, what didn't, whether and where they decide to commit or send another scout... but now the enemies are deterministic and you see exactly what conditions they will consider. If the units always beeline toward the designated target, it's ~~almost~~ ~~like~~ suffering from a bottleneck terrain even in the open: their paths are completely predictable, so you can prepare to meet them in this one tiny spot. Conversely, knowing where they ''won't'' attack allows you to save resources and time by not bothering to build a proper defence on all sides.

* The game cut corners with a combination of [[The All-Seeing AI]] and straightforward algorithms? The downside: if the enemies had [[Fog of War]], most of the time you could not be sure what exactly ''they'' did see, what didn't, whether and where they decide to commit or send another scout... but now the enemies are deterministic and you see exactly what conditions they will consider. If the units always beeline toward the designated target, it's very close to suffering from a bottleneck terrain even in the open: their paths are completely predictable, so you can prepare to meet them in this one tiny spot. Conversely, knowing where they ''won't'' attack allows you to save resources and time by not bothering to build a proper defence on all sides.

* AI units ignore enemies they can't hit (no [[Anti-Air]] capability, etc)? They are asking for either [[Dronejam]] or free shooting range set up on the way to that one high-priority target.

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* Invaders in ''[[Dwarf Fortress]]'' automatically [[The All-Seeing AI|take the shortest route to get into your fortress]], preferentially heading for unlocked doors and avoiding locked ones, even when they have creatures with them capable of bypassing said locked doors. Because of this, [[Video Game Cruelty Potential|it's quite possible]] to set up the entrance to your fortress with two doors with a long corridor full of weapon traps between them and constantly switch which of the two is locked, leaving the goblins marching back and forth through fields of + enormous steel corkscrews+ and *giant swinging iron axe blades* until [[Ludicrous Gibs|blood drips from the ceiling]].

** This can be exploited even more hilariously (if more complicated to set up) by having two rows of 1x1 retracting bridges that are all linked to the same lever in a way so that you have a checkered pattern of bridges that are retracted when the lever's down and drawbridges that are extended if the lever's down. The invaders need to move diagonally every step to get through there, but even if you switch which of the bridges are retracted and which aren't, there is still always a way. If you order a dwarf to repeatedly pull the lever, the goblins will happily march over the bridges until they suddenly vanish under their feet. Using drawbridges instead of retracting ones is less safe (because big creatures can keep the bridges from operating), but even ''more'' hilarious because it flings the goblins!

** ~~The~~ AI will ~~also~~ dodge attacks without taking into account what it's dodging into and what's it dodging away from. Construct a narrow bridge over a deep pit and cover it with crappy wooden extending/retracting spikes, and even the toughest of (non-flying) enemies will dodge right off the edge and start falling. Nothing in the game is immune to fall damage.

** [[Fright Deathtrap|Dodge traps]]: the AI will dodge attacks without taking into account what it's dodging into and what's it dodging away from. Construct a narrow bridge over a deep pit and cover it with crappy wooden extending/retracting spikes, and even the toughest of (non-flying) enemies will dodge right off the edge and start falling. Nothing in the game is immune to fall damage.

** AI units do not react to enemies they haven't seen, including ones in hiding, even if they're attacked by them (though they will attempt to dodge or block those attacks). Units in hiding will also ''never'' be found out by another unit outside a 7x7 box of tiles one is in the center of. Thus, in Adventure Mode, you can stand as little as four tiles away from an enemy and remain in hiding while shooting bolts and throwing rocks at them until they die. The only time this ''doesn't'' work is dark places where you can't see enemies without getting close enough for them to spot you.

** The effects of the Building Destroyer ability are also exploitable- a creature with Building Destroyer level 2 is not only capable of battering down doors and destroying levers and various types of buildings, it actually prefers destroying buildings to doing anything else, including attacking your soldiers unless it's defending itself. If one of your soldiers interrupts a troll in the process of battering down a door, for example, the troll will beat the soldier into unconsciousness or immobility, then leave him or her lying there and return to beating on the door. Building destroyers will also happily stand on top of traps and get stabbed repeatedly, if it gets them close to a destroyable building. Capturing many building destroyer creatures is as simple as [http://dwarffortresswiki.org/index.php/Trap_design#Bait_furniture leaving a Door to Nowhere in the middle of a ring of cage traps]. What's even better, they always do it using melee attacks, never special attacks like fireballs or spray of flesh-melting contagions.

** The effects of the Building Destroyer ability are also exploitable: a creature with Building Destroyer level 2 is not only capable of battering down doors and destroying levers and various types of buildings, it actually prefers destroying buildings to doing anything else, including attacking your soldiers unless it's defending itself. If one of your soldiers interrupts a troll in the process of battering down a door, for example, the troll will beat the soldier into unconsciousness or immobility, then leave him or her lying there and return to beating on the door. Building destroyers will also happily stand on top of traps and get stabbed repeatedly, if it gets them close to a destroyable building. Capturing many building destroyer creatures is as simple as [http://dwarffortresswiki.org/index.php/Trap_design#Bait_furniture leaving a Door to Nowhere in the middle of a ring of cage traps]. What's even better, they always do it using melee attacks, never special attacks like fireballs or spray of flesh-melting contagions.

*** [[Incredibly Lame Pun|Building]] on this, artifacts are indestructible. Put an artifact door, floodgate, hatch cover, or grate near your entrance, put up a marksdwarf post (with fortifications, of course), and prepare to turn any invading building destroyers and any goblins riding them into pincushions. Alternatively, put it in the caverns so you don't have to deal with forgotten beasts.

*** Even those that don't set off traps can be made to activate traps indirectly. They are not bothered by what's on the other side, even if a door is a little warm... and doors hold the liquids to the last - [http://dwarffortresswiki.org/index.php/Trap_design#Building_destroyer_and_trapavoid_traps some setups] let a building destroyer creature hammer on until the door is gone and [[Pressure Plate]] closes the exit while knee-deep spill of magma fries everything in the room, or water flushes the unfortunate off the ledge, etc. Undead and non-organic building destroyers "gain the ability to destroy wooden supports, which generally [[Collapsing Lair|ends poorly for the creature]]", as DF wiki put it.

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** Endermen also have an exploit in their AI that can be abused if used right. Endermen take damage from water and if an Endermen is hostile towards you, exposing it to water will cause it to be neutral and stop attacking you.

* ''[[Terraria]]'' has a similar pathfinding problem. Enemies only know how to reach you in a straight line, meaning a simple thin lava pit on either side of a house means infinite money as the enemies stroll in and immolate themselves. On the flip side, this will usually destroy loot in the underground areas where the lava is too deep. Enemies are also too stupid to walk around an obstacle when you're above them, since they only target you by the y-axis. This allows to effectively lock some enemies on a higher level of blocks (which you can often build on the fly if hotkeyed) while attacking others.

* [[Final Fantasy Tactics]] has a few of these, but they're rare or situational enough that it's generally easier to either get better at the game, or level grind. However, players engaging in [[Challenge Run|challenge runs]] need every advantage they can get, and there are a number of well known tricks for various bosses. The most notable of all, however, is known as the Loss Strategy. Loss in an ability possessed by numerous bosses (in particular, the hardest ones) that can inflict the confusion status with 100% success rate. A confused unit will run around the battle field using random abilities at random targets. The AI is hard-wired to never break confusion unless it knows it can kill the target in two hits. Normally, this is not a problem, but in a solo challenge, when the player is confused and the boss cannot kill him quickly, the boss either does nothing, or uses mostly harmless spells that can't actually kill the player. With no allies to attack the confused character can only attack the boss. This means that many otherwise strategy intensive boss fights end up reduced to 'get confused with enough HP, enjoy a drink while the random AI slowly kills the boss'.

* ''[[Final Fantasy Tactics]]'' has a few of these, but they're rare or situational enough that it's generally easier to either get better at the game, or level grind. However, players engaging in [[Challenge Run|challenge runs]] need every advantage they can get, and there are a number of well known tricks for various bosses. The most notable of all, however, is known as the Loss Strategy. Loss in an ability possessed by numerous bosses (in particular, the hardest ones) that can inflict the confusion status with 100% success rate. A confused unit will run around the battle field using random abilities at random targets. The AI is hard-wired to never break confusion unless it knows it can kill the target in two hits. Normally, this is not a problem, but in a solo challenge, when the player is confused and the boss cannot kill him quickly, the boss either does nothing, or uses mostly harmless spells that can't actually kill the player. With no allies to attack the confused character can only attack the boss. This means that many otherwise strategy intensive boss fights end up reduced to 'get confused with enough HP, enjoy a drink while the random AI slowly kills the boss'.

* ''[[Left 4 Dead]]'' and its sequel has some parts of the map where the zombies somehow become blind to your presence, even if they are within arms reach of you. Due to bugs or just faulty AI navigation, being in certain places causes the zombies to act like they cannot reach you anymore. Similarly, Tanks can suffer the same problem and they will die after some time since it's programed to suicide if it cannot see or reach the survivors after some time has passed.

* In ''[[X-COM]]: Enemy Unknown'' as soon as one alien sees one of your soldiers, their Ethereals and/or high-ranking Sectoids can make psionic attacks [[The All-Seeing AI|on any of your soldiers]]. They also know who has the least resistance and always target the weakest non-mindcontrolled soldier first. Which, of course, means that if you equip a bunch of your most weak-willed soldiers without damage-dealing weapons (they can still be somewhat useful when not being puppets, carrying medi-kits, mind probes, flares, smoke grenades, even heavy ammo for others) and keep them where armed ones won't make reaction-shots on them, mind control is but a nuisance.