High Street retailer GAME is due to open 150 stores at midnight for the launch of Halo 3 next week.
The retailer expects thousands of customers to queue for their pre-ordered game, and will also be opening stores early on the morning of September 26.
"Halo 3 will be a huge event in towns throughout the UK, so we’re pulling out all the stops to help our customers start playing it as soon as humanly possible," said Robert Quinn, operations director at GAME.
"Over 800 GAME staff will be on duty at midnight to serve customers and keep the shelves full.
"Halo 3 is hotly anticipated by thousands of customers who have reserved it months in advance, and we are working flat out to make sure our customers are first to get the products they want," he added.
Earlier this week Microsoft revealed that it would be hosting the UK's official Halo 3 launch at London's iMax Cinema, complete with celebrities, competitions and screenings.