Insomnia56 was the 56th installment of the Insomnia gaming festival, taking place at the National Exhibition Centre in Birmingham, England from December 11-13, 2015. Halo 5 was played in 4v4 competition alongside Hearthstone, Counter Strike: Global Offensive, Dota 2, League of Legends, Rocket League, Call of Duty: Black Ops III, FIFA 16 and Super Smash Bros. for Wii U.
Insomnia56 was the first major open Halo 5 event in the UK, allowing up to 32 teams to register. Taking place shortly before the Halo World Championship 2016 qualifying process started in the UK, the event gave players an early chance to showcase their skills. Epsilon eSports dominated the event, dropping only a single game en route to their second major tournament win.
- Open event, 32-team limit
- Double-elimination bracket, best-of-5 series
A total of £3,000 GBP in prize money is awarded.