AI surrenders when one human remains
AI surrenders when one human remains is a game setting that controls the behavior of the computer-controlled AI.
If this setting is enabled, the AI will surrender as soon as all of the human players except one in the game are no longer alive. It does not matter whether the humans are eliminated, surrendered, or booted.
With this setting enabled in team games, the AI will surrender when only one team with humans remains alive. If this setting is enabled on a co-op game (a game where only one team has humans), this setting will be automatically turned off. Otherwise, the AIs would try to surrender right when the game began.
By enabling this, it ensures that the last person doesn't need to waste their time finishing off the remaining AI. After all, it's a multi-player game.
By disabling this setting, it can help keep the winner more fair in some circumstances. For example, say player A is on the verge of winning - they have a very high income and are finishing off player B. If, for some reason, player A can't make their move, they could get turned into an AI via boot. With this setting disabled, player A's AI will continue to finish off player B and player A will win the game as they would have. With this setting enabled, player B can simply accept player A's AI's surrender.