The principle of NTOD is simple - the player has to search a level, find keys to the gates preventing him/her from proceeding to the next part of a level and discover, obtain and assemble a sacred key - Skullkey, which opens a magic gate into the next level. It's not an easy task at all because various numbers of opponents strive for the same goal. Moreover, when a player dies, he/she looses all the collected items - and that can increase his/her opponent's chances to win the level. The energy of each character is limited and decreases with the length of its life. The environment of individual levels is aggressive, attacks of omnipresent vermin and enemies speed up the decrease of the energy. Laying traps and combining them feloniously with the natural pit-falls of the environment is one of the basic fighting tactics. That all uses up a lot of each character's energy (trap layer and his/her victim) - the fight is thus transferred to magic places - Manna Pools, where the manna can be refilled. The energy can be also recharged outside the Manna Pools - by killing an enemy. Each game environment contains numerous lethal traps, which can be used for elimination of enemies, or, in case of carelessness or inability, even for self-destruction.