You can't stop peer-to-peer file sharing. So the best route to combat it is to subvert it, and turn it around to your advantage. For example, we will release a version of our game that looks like it's been hacked at the same time as a pirate version gets out - usually a couple of days after release.

Our version, which is modified, repackaged and distributed by our user community of around 1000 active participants, looks like the real game, but is in fact a demo. After the third time of downloading the demo, the peer-to-peer user will be very, very frustrated, and will do one of two things; give up or buy the game from us. We subverted the Bit Torrent network for Darwinia very successfully this way, and to a lesser extent eMule / eDonkey.

Arundel also comments on more intrusive copy protection systems, noting that many of them detract from the experiences of legitimate gamers. "We can't win the war on piracy, but if you work smart, you can definitely reduce it," he said. "The golden rule I think is to keep things simple - especially for the legitimate user." (Thanks GilesH!)