From A3! Wiki
There are four types of events in A3! at the moment:
- Troupe Events (or Regular Events) are the normal, troupe/play-associated events such as Nocturnality or Stranger.
- Seasonal Events are virtually the same as a Troupe Event in terms of gameplay, but it uses a different point system.
- Etude Events do not have rewards for ranking, and is the first type of event that's quite significantly different to the normal system.
- Support Events were introduced in 2018. They are similar to a Seasonal Event, but you accumulate Support Points instead of items. They do not feature event cards, but are a ranking event.
- Campaign Events were introduced in 2018 as a way to unlock Main Story chapters faster.
- Training Camp Events were introduced in 2018. They are similar to Seasonal Events, with Training Camp Points instead of items, but also feature additional content such as extra backstages and a Training Camp Leader SSR++ card.