FUNDAMENTALS OF GAME DESIGN, SECOND EDITION
WHY DO WE HAVE CHARACTER LEVELS?
The notion of character levels is so ingrained in the culture of role-playing that most players take it for granted. However, there's no intrinsic mathematical reason why we, as game designers, should implement character levels. We already have experience points as a measure of character growth; why have levels as well?
Levels are convenient in tabletop RPGs because they reduce the amount of bookkeeping required by the player and the GM: A character's characterization attributes change only when the character levels up, except in rare circumstances. However, now that we have computers to simplify the bookkeeping for us, that in itself is not a sufficient reason to use character levels. It's perfectly possible for the computer to gradually give the player additional powers on a continuing basis every time he earns some more experience.
By using a system based on fractional values rather than integers, characters can experience steady continuous growth rather than big “stairstep” jumps in power.
The big jumps resulting from leveling up also harm the player's immersion; they're artificial and don't correctly model the increases in strength that a real person would experience in a training regimen, for example. It would be interesting to see a level-less role-playing game in which the player became aware of his gradually increasing strength without knowing what the actual numbers were. Such a game might appeal to an audience who prefers an immersive storylike experience over knowing their character's precise numeric state; a hybrid of adventure game and RPG, perhaps.
However, there are good entertainment reasons for including character levels in an RPG. First, the levels give players a quick method of comparing the relative strengths of different characters, especially enemies. This is unrealistic but useful when the player is trying to decide whether to include a particular character in the adventuring part or whether to attack an enemy character. Because most games don't display a character's strength visually, the player needs some other way of judging it, and the level provides that. Second, character levels provide players with a goal to work toward and a sense of achievement when it has been attained. Being granted points that they may add to their attributes feels like they are being given a reward, too. Finally, the leveling-up process lets the players decide where they want to distribute their new points, allowing them to upgrade their character as they see fit. If the system was continuously increasing their attributes, they wouldn't have as much control, nor would they notice the difference so much.
In short, character levels reduce the realism of a game but offer a number of useful compensations.
