Epic Games' Fortnite is the most popular video game worldwide.

The Apple vs Epic Games legal battle is getting murkier day by day. The tech giant on Tuesday filed a counter lawsuit against the Fortnite maker, alleging the game developer violated its contract with Apple and seeking an unspecified amount in damages.

“Although Epic portrays itself as a modern corporate Robin Hood, in reality it is a multi-billion dollar enterprise that simply wants to pay nothing for the tremendous value it derives from the App Store,” Apple said in a filing with the District Court for the Northern District of California. “Epic’s lawsuit is nothing more than a basic disagreement over money.” Apple called Epic Games’ movtive “willful, brazen, and unlawful.”

The Cupertino, California-based Apple argues that Epic wants “free access to the Apple-provided tools that uses and—worse yet—it wishes to then charge others for access to Apple’s intellectual property and technologies.” The lawsuit clearly notes that Epic Games has earned over $600 million through the App Store.

Apple continued by saying that Epic Games’ real motive is to get “special treatment” from Apple’s App Store rules. The company also said that the Fortnite developer got access to tools, marketing opportunities, software and most importantly, access to Apple customers through the App Store.

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“Epic’s demand for special treatment and cries of ‘retaliation’ cannot be reconciled with its flagrant breach of contract and its own business practices, as it takes in billions by taking commissions on game developers’ sales and charging consumers up to $99.99 for bundles of ‘V-Bucks,” Apple said in a lawsuit.

Fortnite is one of the most popular games on the planet with 350 million players.

The trouble between Apple and Epic Games began on August 13 when the game developer started using their own payment system within Fortnite,  bypassing Apple’s standard 30 per cent fees. In no time, Apple removed Epic Games’popular battle royale game Fortnite from the App Store. In response, Epic Games’ sued the iPhone maker alleging that Apple’s App Store “monopolistic” practises violate antitrust rules. Later, Apple suspended Epic Games’ from accessing the App Store’s development tools.

Apple has said it would allow Fortnite back into the App Store if Epic removed the direct payment feature. But Epic has refused, saying complying with Apple’s request would be “to collude with Apple to maintain their monopoly over in-app payments on iOS.”.

The legal battle between Apple and Epic Games comes at a time when Apple battles antitrust scrutiny by running the App Store. Apple, in its defence, argued that the App Store has given millions of developers a platform to distribute their apps freely.