Halo, Dragon Age, Mordor up to half price.
Microsoft's Xbox Ultimate Game Sale goes live tomorrow, but the discounted prices are already available via the Xbox Games Store.
Borderlands: The Handsome Collection is 40 per cent off, as is Halo: The Master Chief Collection and Telltale's Game of Thrones season pass.
Download versions of Dragon Age: Inquisition, Geometry Wars 3, Shadow of Mordor, Sniper Elite 3, Slender, Sleeping Dogs and Watch Dogs are all half price.
Even higher discounts go to Far Cry 4, Killer Instinct Complete Edition, Saints Row 4, Terraria and Titanfall - all are 60 per cent off.
Meanwhile, Microsoft's excellent Ori and the Blind Forest is £12, down 25 per cent from £16.
The biggest saving at the moment is Lego Batman 3's Deluxe Edition, which includes all of that game's Season Pass content. Normally priced at £57.49, you can pick up the whole thing for a very reasonable £14.37.
Here's the full list of sale reductions (via NeoGAF):
Battlefield Hardline Deluxe - 40% off
Borderlands: THC - 40% off
Diablo 3 - 50% off
Dragon Age Inquisition & Deluxe - 50% off
Dying Light & Ultimate - 30% off
Far Cry 4 & Gold - 60% off
FIFA 15 - 10% off
Game of Thrones Season Pass - 40% off
Geometry Wars - 50% off
Goat Simulator - 33% off
GTA 5 & Great White Shark - 25% off
Halo: The Master Chief - 40% off
Killer Instinct Complete - 60% off
Killer Instinct S2 - 40% off
Lara Croft & The Temple of Osiris - 60% off
Lego Batman 3 - 75% off
Middle-earth: Shadow of Mordor - 50% off
Mortal Kombat X & Premium - 25% off
NFS Complete - 50% off
Ori and the Blind Forest - 25% off
Outlast - 50% off
State of Decay - 33% off
Slender - 50% off
Sniper Elite 3 - 50% off
Sleeping Dogs - 50% off
Saints Row 4 - 60% off
Tales from the Borderlands 2-5 - 40% off
Tales from the Borderlands 1-5 - 50% off
Terraria - 60% off
ESO Premium - 17% off
Legend of Korra - 50% off
The Telltale Collection - 50% off
The Walking Dead S1&2 - 50% off
Titanfall - 60% off
Tower of guns - 40% off
Watch Dogs - 50% off
White Night - 50% off
Wolfenstein bundle - 45% off
WWE & Deluxe - 50% off