On the long list of ways that some gamers unwittingly invoke the monkey's paw, there are few chants more insidious than this: "Don't reuse assets." The idea that all games should start from scratch, reinventing a perfectly good wheel or putting out one fire just to light another one right next to it, will at best lead to a whole lot of wasted time and money, and at worst a lot of bloated or even dead games. More to the point, as Mass Effect and Assassin's Creed veteran John Ebenger reckons, directly building on established tech can lead to sequels that end up better in every conceivable way.