I've been reading recently about Ehrenfeucht-Fraisse games. It is easy for me to understand it if it's played on two Kripke models: legal moves for both players (Spoiler and Duplicator) are those respecting both accesibilily and forcing relations on associated structures. Furthermore, I understand the equivalence between bisimilarity of two models and winning strategy for Duplicator (although I am not able to formally prove it yet).
But what if we have some vocabulary with more than one binary relation? What if we have relations with arity greater than $2$? How is EF game then played? I would be glad if someone can clarify this.