Several spells / Skills in several games "last for [X] rounds"... How about adding a "round" counter to the turn counter? Allow the GM to "start" combat with the highest initiative roll, and each time initiative reaches back to that initiative roll, the turn counter increases by one?
As a GM, I find it hard sometimes to keep track of how long a spell or skill has been active, it'd be nice to be able to see that the spell was cast on round two, and lasts for 4 rounds... On round 6, I need to deactivate it.
