The artificial intelligence (abbreviated as AI) is a player character controlled by the computer. They are present in single-player games, such as Custom Skirmish and Kingmaker.
AI players serve as basic but challenging enemies: they take the place of other players and play Stronghold in a similar manner: they can manage their economies, recruit units and send them into battle. They also have limited communication abilities and similarly can be interacted with. Their behaviour is hard-coded into the game.
AI players are represented by various characters, who have their own distinct portrait, personality and various gameplay features. Most of them have distinctive castle designs, economic preferences and unit usage. Harder enemies usually use a bigger variety of units and tend to build enormous economies, while easier enemies are restricted to smaller economies and littler armies.
The AI has limited strategic knowledge and thus they are almost always bested by the player: they are meant for having fun during gameplay.
AI players interact in the form of small videos and sound messages, simulating their live appearance. These most often include taunts, boasts, anger over recent events, fear and defeat messages. In the 2D Stronghold games, they also reply to taunts.
Allied AI players will also notify their allies from their sieges and bad situation. They can also be asked or sent for goods, as well as commanded to attack a certain enemy or help out in defending: to these situations, the AI may have either an approving or refusing answer, fulfilling or rejecting the command.
Stronghold Crusader 2 added the "mood" variable, which represents the AI's likeliness of accepting a request. Asking the AI for favours or declining them generally ruins its mood, however it slowly regenerates. When the AI's mood is in the orange or red category, it is very unlikely to fulfill a request.
- The AI usually has its own castle schematics, consisting of most buildings' placements and build order. They try to build castles by recreating these patterns. Defensive units also have their exclusive spot.
- Trade is less restrictive to the AI than the player, as they can sell or buy goods in any amount. Their trade rate however is reduced by trading one packet at a time or in periodic big bulks (depends on game).
- Due to their non-existent mechanic limitations, AI players can place multiple buildings in rapid succession and micromanage their units, as well as having instant reaction to certain events (such as a unit coming into a siege engine's attack range).
- Gameplay is generally easier for the AI player, to somewhat counteract the player's intellectual advantage:
- In Stronghold Crusader: units ignore rally point spread and sometimes walls can be built, even when stone is not present in the stockpile (stone cost is deducted however).
- In Stronghold 2: rats, gong and crime does not appear (with modified castle layouts, this can be avoided), as well as troop and building costs heavily differ; siege camps and siege machines here are freely built (harassment units do not); weapon production is boosted.
- In Stronghold Crusader 2: siege camp attacks are free, as well as war wagons spawn with free missile units; walls can be built for free; trade can be discounted, gold reserves are periodically boosted.
|Stronghold||4 characters, although in the forms of campaign invasions and sieges only.|
8 characters (16 with Warchest), alliances, goods transfer, attack/defend commands, taunts.
|Stronghold 2||8 characters (10 with Deluxe), alliances, basic voice messages.|
|Stronghold Legends||6 characters (8 for Legends Trails), alliances, basic voice messages and avatar indicators.|
|Stronghold 3||5 characters, although in the forms of campaign invasions and sieges only.|
|Stronghold Crusader 2||8 characters (16 with all DLCs), alliances, goods transfer, attack/defend commands.|