Walmart, the largest retailer in the US, is expanding its video game department to accept used game trade ins, which could have big implications for video game retailer GameStop.

Walmart will begin accepting the trade ins on 26 March. The value can immediately be applied towards the purchase of anything sold at Walmart and Sam’s Club, both in stores and online. The traded-in games will then be sent to be refurbished and made available for purchase at Walmart stores.

“Gaming continues to be an important business for us and we’re actively taking aim at the $2 billion pre-owned video game opportunity,” said Duncan Mac Naughton, chief merchandising and marketing officer for Walmart US. “When we disrupt markets and compete, our customer wins. They’ll save money on video games and have the flexibility to spend it however they want.”

Walmart explains the trade-in program will require customers to bring their working video games in the original packaging to the electronics department. A Walmart associate will then scan the UPC code on the case, and evaluate the condition of the game. A trade-in price will be offered, and if accepted by the customer, will be applied to their next purchase.

The choice by Walmart to rollout the program could bring a huge sales boost for its gaming departments at the 3,100 Walmart stores across the county. It could also have a big impact on GameStop, who has had a commanding lead on the used game market for quite sometime.

Following Walmart's used game program announcement on Tuesday, shares of GameStop's stock fell 3.5 per cent on the news.

GameStop saw pre-owned sales increase 7 per cent to $567 million during the 2013 holiday season, making up 18 per cent of all its holiday sales. Walmart is predicting its game business to be worth $2 billion, but didn't detail over what period of time.  Unlike GameStop, Walmart won't just give you cash for the trade in. You must buy another item in the store. 

This isn't Walmart's first try at offering used game trade-ins. In 2009 it began offering kiosks in its stores around the nation, but the program failed and was shuttered in 2010. 

Walmart also offers a trade-in program for smartphones and tablets.