In the game, the player forms a group of up to six characters. Game progress is made through advancing the characters so that they are powerful enough to defeat the increasingly dangerous foes and monsters in the dungeons, obtaining certain items relevant to solving the overall quest, and obtaining information.
The fictional town of Skara Brae consists of 30x30 map tiles containing either buildings or streets (plus gates and magical guardian statues blocking certain streets). Access to one tower in the northeastern and southwestern city corner each is blocked by locked gates. The main city gates, which open to the west, are blocked by snow and remain impassable throughout the game. One street seems to lead south endlessly, by actually teleporting the party back to its beginning upon reaching the portion where the city walls would be.
Certain buildings within the city are special, such as the Adventurer's Guild, Garth's Equipment Shoppe, the Review Board (which is unmarked and must be found first, and is the only place where characters can advance in experience levels), various taverns and temples, and the dungeons. The latter are mazes of various kinds—cellars, sewers, catacombs, or fortresses—full of monsters and riddles, some guarded by magical statues that come to life to attack trespassing player parties.
The first dungeon is the Wine Cellar (1 level) of a tavern, which turns out to be connected to the Sewers of Skara Brae (3 levels) that in turn feature an exit that leads to the otherwise inaccessible southwestern corner of the city where Mangar's Tower, the final dungeon, is located. The tower cannot be entered without a key, however. In the sewers, numerous hints are found, including the name of the Mad God. Finding the Wine Cellar requires the party to order some wine at a specific tavern. There was a hint to this in the manual (Hint: The first dungeon is the wine cellar of the only tavern in town which serves wine. It's on Rakhir Street). However, this hint was not present in the manual included with the C64 release of the game[citation needed]. Upon ordering wine, the party is sent by the bartender to his cellar to fetch a bottle themselves. It is not actually possible within the game to obtain a bottle of wine, nor is it required to proceed.
The undead-infested Catacombs (3 levels) beneath the temple of the Mad God, accessible only if his name is known (the player must type the password to enter). On the lowest level, a Spectre must be defeated to obtain an eye.
If they possess the eye, a statue of the Mad God in Baron Harkyn's Castle (3 levels) will teleport the party to the (otherwise inaccessible) northeastern area of Skara Brae where the next dungeon is located; however, it is not required to proceed to the next dungeon immediately. If weakened too much from the fighting in the castle, the party may elect to leave the area via one-way portals instead at this point and return to the city and the Adventurer's Guild.
Kylearan's Tower (1 level) can only be reached through the teleporter in Harkyn's Castle, requiring any party who wishes to enter to fight through the castle's three levels first. Kylearan the Archmage awaits the party at the conclusion of his tower maze and turns out to be friendly. He gives the party an access key to Mangar's Tower, the final dungeon, but they still have to circumvent the locked gates around the tower by going through the Sewers.
Still reachable only via the Sewers at this point in the game, Mangar's Tower (5 levels) is the final dungeon that has to be overcome to reach Mangar and slay him, provided the party has acquired several items in the other dungeons which are required to best him. At one point within the tower, the party can acquire a key that will allow them to access Mangar's Tower and Kylearan's Tower from the city directly thenceforward, without having to move through the Sewers or Harkyn's Castle, respectively.