By Maria Ward-Brennan US-based game developer Valve Corporation that created Half-Life and Team Fortress is facing a £656m class action in London for allegedly overcharging 14 million PC gamers in the UK. The case details allege that Valve Corporation has shut out competition in the PC gaming market by forcing game publishers to sign up to ‘price parity’ obligations that dictate Steam always has the ‘best price’ and prevents the same games from being sold at a cheaper price on rival platforms. It states that this has enabled the gaming giant to continue charging publishers an excessive commiss…