If you are a Smart Football reader, you know them as constraints. They are the plays that keep a defense honest and allow you to live as close to your id as possible.
The idea is that you have certain plays that always work on the whiteboard against the defense you hope to see — the pass play that always works against Cover 3, the run play that works against the 4-3 under with out the linebackers cheating inside. Yes, it is what works on paper. But we don’t live in a perfect world: the "constraint" plays are designed to make sure you live in one that is as close as possible to the world you want, the world on the whiteboard.