Blatantly cheating AI seem taboo for game authors. Not just speedboost or similar kludge. This tag's for those 'adding pieces to the board'.
Alternate name: Computer players can cheat
The first video game about Cheating AI was released in 1980.
This includes when 'equal' (and without handicapping) AI players are given unique abiliti(es) that are nothing like the abilities given to the human players.