Difficulty levels change the amount of challenge a player is likely to face from a game, either from its enemies, the environment, handicaps to their own equipment, or a combination of these factors. Generally, this only holds true in single-player games, as rules are usually there to challenge human players only. There are several methods of changing this difficulty:
- Changing the skill of the AI (for sophisticated games).
- Bonuses given to the player, for easy difficulty, or weaknesses, for harder difficulty. For example, changing the amount of hit points the player has, or the amount of gold they earn in a turn.
- Bonuses given to the AI, for harder difficulty, or weaknesses, for easy difficulty. For example, causing the AI to do less damage, or spawn fewer enemies.
Difficulty doesn't always have to be linear or fair; the AI in Sid Meier's Civilization series will actually cheat at the highest diffculty levels in order to provide an extreme challenge to the player.