Risk Premium measures the extra risk you take stacking off in an MTT. It’s a measure of survival pressure and a valuable tool for understanding ICM spots. Risk premium is defined as the extra equity you'd need to call someone's shove, compared to a (chip EV) pot odds calculation.
RP = Required Equity (ICM) - Required Equity (cEV) when stacks are fully invested. Each player has a unique risk premium against every other player in a tournament.