In repeated games with imperfect public monitoring, players can use public signals to perfectly coordinate their behavior. Our study of repeated games with imperfect private monitoring focusses on the coordination problem that arises without public signals.

A strategy profile of a normal form game is proper if and only if it is quas-perfect in every extensive form (with that normal form). Thus, properness requires optimality along a sequency of supporting trembles, while sequentiality only requires optimality in the limit.

We show that a strategy profile of a normal form game is proper if and only if it is quasi-perfect in every extensive form (with that normal form). Thus, properness requires optimality along a sequence of supporting trembles, while sequentiality only requires optimality in the limit.