Steam sales sneak up on us. Plentiful leaks mean we generally have a pretty good idea about when they're coming but even so, it's never official until, bam, the green flag drops and the sale is live. Epic, on the other hand, is giving us plenty of notice about its upcoming Holiday Sale, which it announced today will kick off on December 17.Games will be discounted by up to 75 percent during the sale, which isn't bad, but the big hook will more likely be the free games that Epic will be flinging around like a fat guy on a rooftop. Instead of the usual weekly giveaway, the Holiday Sale will see a new freebie every day until the end of the month—15 games in total.