The game centers on simultaneously controlling the Overlord and an army of goblin-like minions to traverse the 3D gameworld and defeat the seven heroes who slew the Overlord's predecessor, and who have since been corrupted by power. Each one represents one of the seven deadly sins.
There are four minion races, each of which have their own colour and abilities. Browns are melee fighters, blues can revive defeated minions and swim, reds throw fireballs at enemies, can put out fires and are immune to fire attacks, and greens backstab enemies and can clear poisonous gas and plants. Minions are summoned from the spawning pits found scattered throughout the game. The player needs to pay life-force, which can be gained by killing creatures, like large bugs, to summon minions. At the start of the game only five minions can be summoned at once; as the game progresses this can increase to a maximum of fifty. In addition to controlling minions, the player can sacrifice them at altars of blood and magic to restore the Overlord's health or mana. Once a forge is acquired, they can be used to imbue weapons and armour to increase the Overlord's abilities.
The player begins in an old ruined tower that has been plundered of its magical artefacts and acts as a central hub for the player. As the stolen tower objects are recovered, new rooms and spells become available for use, and the Overlord's maximum health and mana increase. The player also needs to recover the blue, green, and red minion hives to summon the respective minions. The player can customise the tower with a variety of visual items such as banners and statues; the available visual items differ depending on in-game actions. Armour and weapons can be purchased or improved in the forge. Most defeated enemy types appear as opponents in the dungeon, an arena where the Overlord can fight them again (excluding bosses such as heroes and one-of-a-kind beasts).
While the game claims that the Overlord is evil, the quests show him being more of an anti-hero. It also tracks how corrupt the Overlord is in accomplishing his goals. During the game the Overlord is tempted by each of the deadly sins while trying to kill their corresponding heroes. The player's choices will influence your corruption level, either raising or lowering it. Slaughtering inoffensive townsfolk, stealing gold and other activities can also increase the corruption level. The corruption level changes the way townsfolk treat the Overlord and will also change his appearance, a system similar to Fable. As corruption increases, the Overlord's armour will become more devilish with horns protruding out of the back, shoulders, elbows and knees and he will acquire a black aura. The corruption level also determines which game ending the player sees and which high-level spells they can cast.
The game offers several multiplayer modes, Slaughter, Survival, and Pillage. Slaughter pits two Overlords against each other in a head to head combat with potentially hundreds of minions. In Survival, two Overlords team up against large armies of enemies. Pillage is a competition in which two Overlords and their minions compete to see who can pillage and plunder the most gold in a selected amount of time. The Xbox 360 version provides voice chat over Xbox Live. In the PlayStation 3 version Raising Hell, the game features a mini-map on screen to help the player navigate through the game's world.
Plot
The game begins where Gnarl and the Brown minions awaken the Overlord from his tomb. From here they suit him in his armour and proclaim him Overlord in his old and dilapidated tower – the previous Overlord having been killed by heroes, ready to reconquer the lands. The Overlord first turns to the Mellow Hills, where the Halflings and their leader Melvin Underbelly are using the townspeople of Spree and Red minions as slave labour. The Overlord storms the Halfling Homes, slaying Melvin and reclaiming the Reds and Spree (to the peasants’ delight or disgust depending on whether the Overlord returns their stolen food). Castle Spree however has come under attack by bandits. After flushing them out, the castle mistress Rose offers her service to the Overlord. At Evernight Forest, the roots of a tree where Oberon Greenhaze sleeps cover the Elves' home, nearly extinct after being ransacked by Dwarves. The Green minions are found and Oberon is slain. The Elves' sacred statue, however, has been stolen by the Dwarves, angering Jewel, the Thieving Hero, who wanted to steal it for herself. At Heaven’s Peak the town is overrun by zombies and demons. Here the Overlord gains the Blue minions. At the town’s inn, it is discovered that town leader Sir William the Black had fallen for a Succubus, calling off his wedding to Rose’s sister Velvet. Killing Sir William in Angelis Keep, Velvet offers her services to the Overlord and he must choose between her and Rose.
The Overlord then turns to the Dwarven Golden Hills and their leader Goldo Golderson, who has become greedy for gold. Here the remaining enslaved Elves claim the last of their women are being held in the Royal Halls of the Dwarven Keep. Meanwhile, at the Dwarf construction site, Gnarl recommends that the Overlord stash a few minions inside the Elf sacred statue and allow Jewel to take it in order to follow her to her homeland, the Ruborian Desert. Back at the Royal Halls, where Goldo is defeated, the Overlord can either take his stash of gold or free the remaining Elf women before the halls collapse. The Ruborian desert is found and Jewel is captured and interrogated. An enraged Kahn the Warrior, protective of Jewel, strikes back and the Overlord now has to save Spree and Heaven’s Peak from his wrath.
Back at the tower the minions submit to the previous Overlord who has secretly possessed the Wizard, originally father to Rose and Velvet, and who now lays claim to his previous title. The old Overlord tells the current one that he was originally the eighth hero who came to slay him, yet fell from a great height and was left for dead by his companions while they looted the Tower. The Old Overlord however put him in the sarcophagus to heal his wounds in order to use him to defeat the other heroes. The Overlord battles the old Overlord, during which the old Overlord brags of being responsible for the corruption of the heroes. Upon the old Overlord's death, the Overlord reclaims his tower and minions. Depending on the Overlord's corruption and choices throughout, the ending will show 4 of 8 different ending cutscenes where either the Overlord is met with bliss and praise or he pillages and scorches the land and tortures the inhabitants. Regardless of the player's unique ending, the Jester is shown performing some sort of ritual, with Gnarl narrating "Evil will always find a way", opening up the events for Raising Hell.
