Codemasters is offering a selection of its games at a pay-what-you-want basis as part of a new Humble Bundle.
The money raised from the Humble Bundle will be contributed to Special Effect, a charity dedicated to using technology to enhance the quality of life of people with disabilities.
For $1 or more players can purchase Overlord, Overlord Raising Hell (Expansion Pack), Operation Flashpoint: Red River, Operation, Flashpoint: Dragon Rising and Rise of the Argonauts.
Those that spend over $6 will also receive DiRT Showdown, DiRT 3 and Overlord 2.
The games are only redeemable on Steam and will be redeemed as a single unit. Purchases under $1 will not receive anything.
The first Humble Indie Bundle launched in 2010, and the company says its various promotions - from further indie bundles to collaborations with publishers like EA and Deep Silver - have raised more than $30 million for charity.