All Californian branches of US retail chain GameSpot now have to warn customers about used games that demand players buy an online pass to access some of their features.
As reported by Kotaku, for the next two years the store has to place signs on used game shelves informing customers they may have to make an additional purchase.
The new rule is a result of a class action lawsuit brought against the company by law firm Baron & Budd who alleged that GameStop was misleading customers in an attempt to maximise profits "without paying any royalties to video game publishers or developers."
"We are pleased that as a result of this lawsuit, we were able to obtain complete restitution for consumers, with actual money paid out to people who were harmed by GameStop's conduct," commented Baron & Budd attorney Mark Pifko.
"The in-store and online warnings are an important benefit under the settlement as well, because if GameStop discloses the truth to consumers, it is unlikely that they will be able to continue selling used copies of certain games for only $5 less than the price of a new copy.
"In fact, we already know that not long after the lawsuit was filed, GameStop lowered prices for used copies of many of the game titles identified in the lawsuit."
Californian GameStop customers enrolled in the store's customer loyalty program who purchased qualifying used games can claim a $10 check and a $5 coupon as compensation. Those who aren't in the loyalty program can claim a $5 check and a $10 coupon.
Baron & Budd is now looking at bringing similar suits against GameStop in other US states.