How high do you set your goals? In creating its second expansion pack for its Space Marine-clobbering strategy game Warhammer 40,000: Dawn of War, developer Relic says its goal is to make Dark Crusade "the best expansion for any game, ever."

How? First by sheer weight of numbers. There are two new races - the Necrons and the Tau. The former are built for players who like to slowly suffocate their opponents. They're creepy, skull-faced robots on a monster land-grab: their rate of production is accelerated by the amount of territory under their control. They don't need cash; their units are free other than the time taken to produce them.

Leading the charge is the Necron Lord, able to summon mechanical scarabs that can shred buildings and infantry, turn into the five-story Reaper form (complete with robotic scythe), and, best of all, resurrect an entire army. Imagine the look on your opponent's face, when just as he thinks he's won the day, chunks of robo-metal re-arrange themselves into a perfectly healthy, supremely angry army. As their HQ is upgraded, it gains turrets, mobility and the ability to teleport across the map.

The Tau are about combination and ranged attacks. They whittle down enemies from afar with plasma weapons and railguns, then join forces with the skirmishing Tau to close right in on an army and rip them apart. The Kroot can cannibalize the dead, providing a permanent health boost for the army. Those players who favor quick raids and guerrilla ambushes should find the Tau the perfect partners.