Decision Trees, state mechanics, Tactics & strategy

'Decision trees are evaluated from root to leaf, every time. For a decision tree to work properly, the child nodes of each parent must represent all possible decisions for that node. If a node can be answered "Yes, No, Maybe", there must be three children, Yes node, No node and Maybe node. This means there's always some lower node to traverse, until reaching an end node.' - Michael House march 25 2013

https://gamedev.stackexchange.com/questions/51693/decision-tree-vs-behavior-tree



Having decision trees really helps AI feel more real by making choices similar to what a player would make such as can it see the player? Yes, no or maybe? If yes then it can give chase or sound an alarm or attack. if no then it can continue on its patrol route, however if its maybe in which maybe it heard the player or say something in the shadows it may go into an alert state to check out what the disturbance was. Basically starting at 0 and moving down a tree of choices. Another example is if the AI is using a ranged weapon with ammo, such as does it have enough ammo? Does it need to take cover while it reloads? Does it need to swap weapons so on so forth.