neumi5694: In most games I could well do without character levling.
The enemies level with you anyway, so ... what for?
eric5h5: They shouldn't level with you, but if they do then the game is bad. As to "what for," it's so you can go back to an area after leveling and curb stomp the enemies that were giving you trouble before. Which is fun. And that's why enemies that level with you are bad.
But it's perfectly reasonable for enemies to get stronger as the dungeon level increases.
In other words, when you go down a level in a dungeon (or up a level in a tower), it makes sense for the enemies to get stronger.
Darvond: I dunno, a lot of games got away with a Z axis for a while. Maybe they were onto something.
Except that, in some games and game engines, the Z axis is not the vertical axis. (In Super Mario 64, for example, Z is on the ground (perpendicular to X), while Y is the vertical axis.)