Nearly every id Software game on Valve's digital distribution network Steam will go for 50% off this weekend, the Half-Life developer announced today. This offer even applies to the id Super Pack, which includes everything from their earliest classics to more contemporary games like Doom 3 -- 22 games in all, for a measly $34.99. Enemy Territory: Quake Wars appears to be the only major id title not receiving the sale treatment, as its price is still listed at $29.99.