From Castle Wiki

An Actor is an object in a card, such as the player, a wall, a coin, a ball, or whatever you decide.

An actor placed in the scene.

All actors are designed and created from Blueprints, but there can be many actors all using the same blueprint. Actors have a position in space, can collide with each other, and can refer to each other with Tags. For more information about the relationship between actors and blueprints, see Blueprint.

Actor-specific state

Although actors derive all their initial properties from their Blueprint, their state can change as the deck is played:

  • Each actor has its own position and layout in deck space.
  • Individual actors can store different Variables.
  • Individual actors can gain and lose Tags.