Level up

I am currently thinking of a formuls based XP system, rather than an arbitrary one that requires a table.  You get between 0 to 3 XP for an average encounter- depending on how major the encounter is.  Levels require 10x level xp to attain.
Therefore level 2 requires 20xp, then 30xp for level 3, 40 for level 4, and so on.
Once levelled, current xp is returned to zero, but you can carry any points left over.
Each level, players can upgrade their characters by a certain amount.
Simple and saves lots of bullshit like class tables.