Explosions, blood, fanatic space marines, and insane cultists are just some of the common elements players have come to expect from the Warhammer 40,000: Dawn of War game series. Dark Crusade, the latest expansion to this award-winning real-time strategy (RTS) game, introduces two additional races, the Tau and the Necron, bringing the total count to seven distinct factions (including the Imperial Guard from the Winter Assault expansion), each specializing in their own type of strategy. Unlike most expansions, this one doesn't require the player to own the original Dawn of War to play. It is completely functional game, and having the original game and the previous expansion will unlock previously introduced factions in multiplayer. Otherwise, Dark Crusade's multiplayer game will be limited to only the Tau and Necron.

Being a sort of hybrid stand-alone expansion isn't the only way Dark Crusade breaks from convention. Dark Crusade's campaign doesn't follow the linear style of storytelling that Dawn of War and the Winter Assault expansion followed. Instead, all seven races find themselves on a planet called Kronus, which sits on the edge of the Human Empire and was recently conquered by the Tau. Some of the oldest wars were fought on the surface of Kronus, leaving some deadly secrets behind, including a mechanical race known as the Necron buried beneath the surface. The player gets to choose which race to play, each with a unique storyline based on their motivations for coming to Kronus. Afterwards, they are brought to a flat turn-based campaign map planet, where they choose which adjacent territory to invade, like a brutal game of Risk.

The goal of the campaign is to eliminate the other six factions, which is done by conquering their heavily fortified home territories. Defeating a faction on their home turf is no easy task; and that means completing multiple mission objectives. Each territory contains a few nasty surprises, so it's likely that many players will want to take easier targets and collect bonuses before going straight for a foe's throat. Some territories give strategic bonuses like extra starting resources, a higher population cap, or the option to purchase a pre-built base at the start of the mission, which can cut base construction and research time in half. Gaining these bonuses requires players to embark on special missions that don't necessarily mean obliterating your foes. Some missions are a race against time, as you scour the map in search of special units, or possibly a competition to control and hold the most relic points.

Most territories will give access to Honor Guards who are fully upgraded, powerful units who appear at the start of a mission without taking away from the population cap. Honor Guards can only be purchased on the map screen, so if they die in combat, and can only be purchased in between assaults. They are invaluable, since they offer a first line of defense against early attackers. This is important, because the computer always seems to know where you are, and will send forces to wreck your base almost right away. In most cases, the weak starter infantry units that a base produces will be barely enough to repel the first strikes, and the player will need to struggle to keep up against further attacks. This is also where having a powerful Commander will come in handy.

The Commander is the only persistent unit the player has. It is the only unit that can initiate attacks on the campaign map, so players need to be thoughtful in how they move him around. Hitting certain benchmarks like racking up 5,000 kills, eliminating opponents from the planet, and successfully defending territories will score you points to purchase upgrades. These include new weapons, stealth capabilities, shields, or stealth detection. Aside from the added firepower, the Commander also has one or two powers that strengthen other units. Almost immediately, a Commander will become a player's most valuable asset, but never powerful enough to dominate a mission on his own.