Just Compensation is a tier 2 skill in Jack's The Hero of This Story skill tree. It increases Jack's magazine size and grenade damage, with the bonus increasing for every grenade missing from his supply.
This skill makes the common habit of holding grenades for emergencies/clearing out areas less useful, as it promotes having an empty grenade reserve.
As Jack's Cache and On My Mark provide reliable sources of grenades through combat and using your Action skill respectively, it can be wise to completely use up your remaining grenades before entering a combat zone. The grenades will soften up enemies, Just Compensation will improve your staying power through improved magazine size, and any grenades thrown via Jack's Cache and On My Mark will gain a significant damage boost.