Computer graphics may once have been driven forward by the needs of architects and designers, but those times have now passed. The centre of action has switched to the entertainment sector - particularly animated movies and computer games. While a few architects have shown an interest in the design of virtual space, there has been little flow the other way. But games software can be remarkably effective as an architectural tool. We look at how the more bloodthirsty kind of computer games can be subverted for peaceful purposes.