"Once you start Call of Duty: Black Ops' multiplayer you'll notice this game offers a lot more customization than previous Call of Duty titles. CoD Black Ops is actually the first game in the series to offer up this level customization. Unlike Modern Warfare 2, Black Ops uses a currency system to purchase unlocked upgrades, perks and weapons. Want to know how it works? We're here to help! Check out our customization video, and then keep reading for extra tips."