SpecialEffect's flagship fundraiser, One Special Day, is due to take place this Friday, October 7.
During that day, revenue from partner studios will be donated to the charity, with the participating games available via the One Special Day Steam Promotion or, for mobile titles, directly on the event's website.
Over 90 studios are due to participate, via the sale or other initiatives, including EA, King, PlayStation London, Sumo Group, Xbox, and more.
It's too late for companies to sign up for the Steam sale – which is going live on October 6 and will remain on until October 9 – but there is a Just Giving campaign open throughout the event.
At the time of writing, it had already raised £115,000.