In the previous chapter, we have considered the problem of implementing a given social choice correspondence in strong Nash equilibria. In order to do this, we had to find a game form such that at each profile, the set of strong Nash equilibria of the resulting game coincided with the values of the social choice correspondence at this profile. The particular game form solving this problem was usually of minor interest; its main role was to establish the general result about the possibility of implementation. Actually, in some of the situations considered the game form could be criticized for its complexity, each player having to state whole profiles and outcomes compatible with this profile according to the given social choice correspondence. The informational requirements would be quite considerable in any actual play of the game.