While the Overlord himself can also fight in combat with various weapons and armour types that gradually become available and the ability to cast spells to either help minions or hinder opponents, the majority of tasks are performed by the minion hordes. While minions retain many abilities including using scattered items as weaponry and armour, carry large objects in a group, turning cranks and finding treasure, minions can now also operate siege weapons, ships/boats and other war machines and, once captured, can mount and ride wild animals to help in combat and overcome obstacles. The Overlord also has the ability to occasionally take direct control over the current strongest minion to lead the rest through the use of the "Possession Stone".
The Overlord and his minions reside in a dark tower in a dimension known as the "Netherworld", where the Overlord builds up his minion forces by harvesting life-force from fallen creatures that, when gathered, can be brought back into the real world as a minion by summoning them through Minion Gates scattered across the landscape and through the Overlord himself in the less common Netherworld Gates. Treasure accumulated over time can also be spent on upgrades for the tower, whether they’re upgrades for gameplay or just decorative, along with large contraptions and magical objects that the minions can be ordered to return to gates, thus the tower. The choice system returns once more in Overlord II, where at certain points during quests that can be taken providing two paths; the Destruction Overlord that focuses on destroying towns and killing all in his path and the Domination Overlord that rather focuses on enslaving defeated foes or neutral parties to worship and work for him. The choice themselves not only affect the story and interactive with NPCs, but can alter the look of the Overlord and allow certain powers to become available. Other choices such as choosing a mistress now allow the Overlord to have multiple mistresses and can (re)designate any to be the primary mistress at any time.
Besides the single-player campaign, players can play various multiplayer modes online and local, both competitive and cooperative. Competitive modes includes Dominate, where rival player Overlords attempt to capture sections of the map, and Pillage where they must capture large portions of treasure. Cooperative, on the other hand, sees player Overlords working together to either defend against a constant onslaught in Survival or attack powerful foes in Invasion.
Plot
A generation has passed since the events of the first Overlord, with that game's Overlord now the ruler of the Abyss after being trapped following the events of Raising Hell. The Tower Heart was broken shortly after the old Overlord's disappearance, causing a cataclysm, which destroyed much of the old land and started a magical plague. When the survivors fled to new lands, the Glorious Empire came into being and it began to take control of the new lands, while purging all magical creatures. The old Overlord's mistress gives birth to his child, the "Overlad". The Mistress then takes the child to the mountain village of Nordberg and leaves him to grow up there, where all of the villagers (except a girl named Kelda, the Overlad's only friend) fear him, referring to him as "Witch-Boy". The brown minions find him and help cause local havoc. When the Glorious Empire besieges Nordberg, the villagers offer him up to save the town. A yeti, having been freed by the Overlord during his escape, rushes over an ice-covered lake, causing the ice sheet to break, freezing both the Overlord and the yeti until the Minions take him to the Netherworld. The Overlad is raised by Gnarl and the minions as the new Overlord while the Glorious Empire expands its borders.
Upon coming of age and passing Gnarl's tests, the Overlord scouts the Nordberg countryside with the Brown Minions, encountering a band of fanatical environmentalist elves led by Florian Greenheart, who try to prevent him from slaying baby seals, and end up taking in the yeti. Tracking the elves to one of their many Sanctuaries, the Overlord recovers the Red Minions, and uses them to destroy the Sanctuary, earning the wrath of the elven Queen Fay. The actions of the Glorious Empire lead Gnarl to classify them as a serious threat, and the Overlord heads out to both conquer the world and destroy the Empire. This begins with the Overlord capturing Nordberg, taking a now adult Kelda as his first mistress, and choosing to either enslave or destroy the village, along with an Empire governor named Borius. After melting the glaciers to free up a sailing ship, the Overlord and his horde travel to the flooded Everlight Reef, so they may access the elven lands of Everlight.
On arriving, the Overlord finds that Everlight has already been captured by the Empire, with the town being used as a resort by Empire nobles. After finding the Green Minions in the jungle and recovering the Green Hive from a nearby Empire fort, the Overlord takes control of Everlight, taking Juno (a seductress accused of being a witch by other Empire women) as a second mistress, and either kills or enslaves the town's inhabitants. Juno tells the Overlord how to access the Empire's interior territories, but while attempting to sneak in as a local governor, the Overlord falls into the slums. While exploring the slums, the Overlord comes across the Arena, a large Colosseum-like structure where magical beings are killed in gladiator-based games. The Blue Minions are rediscovered in the prisons underneath the Arena, but, before he can escape, the Overlord is apprehended by Marius, adviser to Emperor Solarius and thrown into the Arena. The Overlord defeats the waves of opponents including the yeti from before, in the process destroying a portion of the arena. Although Solarius and Marius flee, the Blue Hive is recovered, and the player has the option of either capturing the yeti, or killing it. Back at the Netherworld tower, the Overlord is visited by a mysterious woman who Gnarl vaguely recognises. The Overlord travels to the Wastelands (the site of the old Overlord's tower), and is tasked by Gnarl with finding the twelve shards of the Tower Heart. After encountering the elves' final Sanctuary, Queen Fay and Florian help the Overlord to reassemble the Tower Heart while Florian is captured by the Empire after leading the Overlord to the shards, and Fay regretfully allows the Overlord to drain four shrines to power up the Tower Heart. As this is not enough, the Overlord then drains Fay of her magical energy, corrupting her and taking her as his third mistress.
