Challenges are a special player-versus-AI skirmish game mode introduced in version 3.3.
Challenges pits one or two players (either one human and one AI or two humans) alone against three AI enemies that start with a large base and violate certain rules of the game (most often capable of building stolen tech units). Challenge maps are made with an "uncontrolled difficulty mindset" so the gameplay will be asymmetrical.
Challenge maps use standard skirmish settings, which allows the handicap to be changed through the difficulty option and for the Mental AI Boost to be enabled. However, note that the following settings are enforced by the client:
- Building off ally bases, naval combat (if the map has enough water) and Stolen Tech Units are enabled.
- Ally Change Ingame is disabled.
- The number of starting units is set at zero.
- If the enemy in a challenge is a specific subfaction, that subfaction cannot be chosen by players.
- The colour used by the enemy is not selectable by players.
- Spectators are not allowed.