Epic Games just fired another shot in its long-running battle with Apple. The gaming giant announced a new rewards program offering players 20% back on purchases made through its direct payment system, effectively undercutting Apple’s App Store commission model.

Epic Games' fight to change Apple's App Store rules has been an expensive activity for the game maker, with CEO Tim Sweeney believing it could ultimately cost the company more than $1 billion.

It has cost Epic Games more than $100 million to challenge Apple's App Store rules in the ongoing Apple vs. Epic Games legal battle, Epic