Yes they are, atom is in isolation, cell has membrane, we have a body we have isolation and encapsulation in physics/chemistry/biology. In actor model message passing is interaction. Since you mentioned game, check out https://github.com/aeplay/kay, which is the isolation "objects" for https://github.com/citybound/citybound "physics engine". On multiple bank accounts, well an account is an actor, so there is no problem there, please have a look at http://proto.actor/blog/2017/06/24/money-transfer-saga.html