Your only option is scripting. That's how pros do it.
No.
Basically what i do, Say that your RPG has a resource thing so when you chop down a tree, it gives EXP.
After you then add exp, it does this:
Client > VCE_IfVariable [EXP_Woodcutting] >= [<var:cl:Woodcutting_RequiredEXP>]
[0] OnVariableTrue > Client > VCE_ModVariable [EXP_Woodcutting] Subtract [<var:cl:Woodcutting_RequiredEXP>]
[0] OnVariableTrue > Client > VCE_ModVariable [LVL_Woodcutting] Add [1]
[33] OnVariableTrue > Client > VCE_ModVariable [Woodcutting_RequiredEXP] Add [65]
[34] OnVariableTrue > Client > ChatMessage [<color:ffff00>Level Up!]
So what that'll do, Is say when you start your character, you have to get 50 EXP to level up. Then when you do, You then have to get 50+65 EXP to level up. Then it keeps adding up, making it harder.