Floors and Complexity
Floors
RS 2 Gold: There are a total of 47 floors underneath Daemonheim. You can only access floors which are equal to half your dungeoneering level or less. Also, you must play through a floor to be able to access the next. For example, to access floor 17, you need a Dungeoneering level of at least level 36 (36/2=17) and you must have completed floor 16 at least once. Floor 1 is closest to the surface; floor 2 is below that, all the way down to floor 47. As you go deeper, you gain more XP, but the monsters become more powerful. If someone in your party doesn't have the required level to proceed to the next floor, the floor will be repeated until everyone can proceed to the next floor.
Complexity
The complexity determines what the players start with once inside the dungeon, as well as which skills can be used. You should always play at the highest complexity possible to maximize your XP. Both free players and members can access all complexity levels, but only members can use members-only skills. When you complete a floor at a lower complexity, you will always play at the next complexity on the next floor. The different complexities do not have level requirements, but to play at a higher complexity you need to have completed floors at all the lower complexities at least once.