Leveling is the standard way of progression on a lot of multiplayer games. Very few games have made leveling in multiplayer a rewarding experience and the majority haven’t made it difficult (without being annoying) or balanced.
The leveling system in Ill-walkers has 32 levels per conversion, and 8 conversions initially on disc. 3 extended conversions (48 levels) per expansion pack. You level up by gaining exp, the exp calculation is detailed here --> exp calculation.
There are two different leveling systems in Ill-walkers, Generic and Evolved. Generic leveling is similar to classic prestiging systems in multiplayer games (Call of Duty, ect...), this is where you convert after completing the maximum level (automatic on Ill-walkers, you go from level 32 to *next conversion* level 1 while playing the game).
Evolved leveling system is a lot. There are challenges set for each prestige and an increasing exp de-buff multiplier that is applied each conversion. There is a few 'non-game changing bonuses' for playing with Evolved leveling (detailed below).
These two conversion systems are playable alongside each other, you change conversions in the settings.
Playing on the Evolved leveling system gives the player some bonuses.