Early events are random events that can occur during the early portion of a game.
Colonization events are dilemmas players must resolve when they first colonize a planet.
Galactic events are random events that can occur during a game that offer a bonus and/or penalty to all players. Unlike other event types there do not feature an ideological choice.
Mega events are a type of optional random events. The player can define the frequency of Mega Events during the creation of a new game.
Crises are special events introduced with the Intrigue expansion. Unlike other events they have multiple stages and can result in failure if specific conditions aren't met.