The sound of digging pervades Dungeon Keeper 2. Bullfrog's 1999 real-time strategy game involves the construction and operation of a dungeon and labyrinth in a gloomy underground world. There are always chambers to be excavated, minerals to be mined and exploratory tunnels to be dug in order to expand your area of play. The imps, tiny magical creatures that comprise your basic workforce, are continually scraping and picking away at the ground somewhere at your bidding. It's a pleasantly double-edged sound – industrious, but also subversive. You're eating away at the world around you, undermining, corroding, tunnelling like a colony of termites. And if your imps run out of orders and stop working – you'll see them sit against the wall and light up cigarettes – you might still hear digging. That would be the sound of one of your rival keepers chipping away at the rock in your direction, heading inexorably towards you.
Building and undermining at the same time – that's the centre of the appeal of Dungeon Keeper 2 (DK2). The player must design and construct a detailed and multi-functional underground world to perform a number of tasks, but also revel in destruction, murder, torture and slavery. Indeed, those are the tasks. This is a dungeon, after all. In other hands, DK2 could have been a recipe for dreary sadism. But Bullfrog put together a world that was all about beautiful, rich, detailed, absorbing, funny sadism.
A typical game begins with a single chamber: the Dungeon Heart. This, the core of your realm, is where your treasure is stored and is also the source of your health. If the gigantic pulsing muscle (you heard me) at the centre of this room is subjected to a sustained attack by your enemies, it will die, and if it dies, you die. So the dungeon must be built up around it: rings of defences, and facilities that will attract and sustain an army of happy, belligerent monsters. These start with a lair, which gives them somewhere to sleep, a hatchery, which provides chickens for them to eat, and a training room for them to hone their combat skills. Specialist structures like libraries, workshops and torture chambers attract specific kinds of monsters, although most of the creatures in DK2 are familiar Sword & Sorcery types. Later, swankier rooms include glamorous casinos and not-so-glamorous combat pits, which either make creatures happier by giving them R&R or make them better killers by sending them to A&E. Some of them also seem to enjoy recreation in the torture chamber, but we're not here to judge. And there's the digging – always with the digging. Chambers and tunnels must be excavated and gold must be found and mined. Pick, scrape, shovel, etcetera.
Laying out rooms and corridors, assigning functions to them, attracting employees and specialists … At this point, a particular strain may be identified in DK2's twisted DNA: it is obviously a descendant of Bullfrog's Theme Hospital, which was developed in parallel with the original Dungeon Keeper and released just months before it in 1997. So where are the patients? In Theme Hospital, the aim was to keep the members of the public who strayed into your world alive, and they mostly only died by accident. Mostly. In DK2, the roaming members of the public are tedious, bellowing heroes, representatives of the so-called forces of good, and if they find their way into your realm they need to be subjected to a deadly form of triage. Your troll-filled workshops can build traps, from simple passive defences like doors to the all-time classic: a rolling Indiana Jones-style boulder that can crush everything in its path. In between are all kinds of dangling skeletons and poison gas vents. Many happy hours can be spent ringing your lair with fiendish killing-chambers, hidden triggers and secret passages. Softened up by the traps, surviving heroes can be set upon by your creatures and beaten to within an inch of their life. Enemies are mostly just stunned if they lose a fight – while thus poleaxed, they can be dragged to a prison. There, they will either starve and rise as a skeleton to join your armies, or they can be dropped in a torture chamber, where they'll be tormented by whip-wielding dominatrices called Mistresses (a saucy element the game revels in) and become allies. Your own creatures can, when stunned, be dragged back to the lair to recover. If the imps are too late and the creature dies, they can be dragged to a graveyard and buried, later to rise as a vampire. It's Theme Necropolis.
The original Peter Molyneux-designed Dungeon Keeper had a similarly detailed internal ecology and other charms, but doesn't often come out of its box nowadays, while DK2 continues to be a treat. It's rare that a sequel can lose a talent like Molyneux and still exceed its ancestor, but Bullfrog's Colin Robinson managed it. DK2 is a vast graphical advance on the original, substituting fully 3D creatures for sprites and introducing a depth and richness to the interiors that is truly atmospheric. The player interacts with this gorgeous environment via a disembodied hand – a feature carried over from the original, which Molyneux was to re-use in Black & White (2001). The hand allows a much deeper tactile involvement in the game environment than a simple cursor. Not only can creatures and gold be picked up, encouraging slaps can be dispensed – including animals you first think are just decorative, like the chickens in the hatchery and the rats in the prison. DK2 is also far funnier than the original, with a jokey narration by Richard Ridings (see box) and a seemingly inexhaustible supply of in-game jokes and Easter eggs. Humour was a strand of Dungeon Keeper – it's at the malevolent heart of DK2. That might be its real advantage over the original game. Molyneux's original game was part of his career-long interest in bending and manipulating morality within games, from Populous (1989) to Fable (2005). 2001's Black & White, which made choosing between good and evil the central dilemma of an RTS game, could be considered the lost sequel to DK2. But what makes DK2 really refreshing is that it's less self-conscious about its immorality than its predecessor – it's just raucous good fun.
So what's the point? There must be more to life than lounging around in a luxurious underground fortress-casino surrounded by servants, treasure and leather-clad lovelies. Well, maybe. In the simple skirmish and multiplayer games, there are other keepers advancing towards you, and they must be defeated. But in the campaign game, it's the forces of humanity, moral rectitude, motherhood and apple pie that are trying to put a stop to your subterranean shenanigans. Those roving bands of heroes must be defended against while you bide your time and build forces strong enough to pursue them to their source and kill their lord so the Horned Demon can show up and claim that level's "portal gem". The keeper advances from land to land, undermining and doing battle with the resident heroes and collecting these gems. As each land is corrupted from beneath, it turns brown and withered on the campaign map - your progress is an advancing stain. All of this serves the ultimate aim of a final confrontation, in which the keeper burst forth onto the surface of an unsuspecting world ...
... Which never happens. Strangely, much of DK2 is just a set-up for a sequel, Dungeon Keeper 3, trailed within the game but cancelled early in 2000. Unless the franchise unexpectedly rises from its tomb, the keeper is condemned to toil within the bowels of the earth forever. It could be something from Milton or Dante. All that digging and undermining, only to find that you've just been getting deeper and deeper into the pit; perhaps a fitting fate for an evil overlord.