You can take a look at this for ideas. This is the level system script I used for handling Level ups and for the player learning new skills... and for increasing their damage multiplier based on their level:
; Level System - by Plystire
; Requires Ply's Mod V1.07 or Higher
desc = Level System
;Triggers
:state=0:hudreset,hudx=50,hudy=15,hudimagefine=gamecore\huds\Ply'sMod\expbarfill.png,hudname=expbar,hudmake=display
:state=0:hudreset,hudx=50,hudy=15,hudimagefine=gamecore\huds\Ply'sMod\expbar_0.png,hudname=exp0,hudmake=display
:state=0:hudreset,hudx=50,hudy=50,hudimagefine=gamecore\text\Blizzard.bmp,hudname=learnblizzard,hudhide=1,hudmake=display
:state=0:hudreset,hudx=50,hudy=50,hudimagefine=gamecore\text\Blizzara.bmp,hudname=learnblizzara,hudhide=1,hudmake=display
:state=0:hudreset,hudx=50,hudy=50,hudimagefine=gamecore\text\Blizzaga.bmp,hudname=learnblizzaga,hudhide=1,hudmake=display
:state=0:hudreset,hudx=50,hudy=50,hudimagefine=gamecore\text\Thunder.bmp,hudname=learnthunder,hudhide=1,hudmake=display
:state=0:hudreset,hudx=50,hudy=50,hudimagefine=gamecore\text\Thundara.bmp,hudname=learnthundara,hudhide=1,hudmake=display
:state=0:hudreset,hudx=50,hudy=50,hudimagefine=gamecore\text\Thundaga.bmp,hudname=learnthundaga,hudhide=1,hudmake=display
:state=0:hudreset,hudx=50,hudy=50,hudimagefine=gamecore\text\Fire.bmp,hudname=learnfire,hudhide=1,hudmake=display
:state=0:hudreset,hudx=50,hudy=50,hudimagefine=gamecore\text\Fira.bmp,hudname=learnfira,hudhide=1,hudmake=display
:state=0:hudreset,hudx=50,hudy=50,hudimagefine=gamecore\text\Firaga.bmp,hudname=learnfiraga,hudhide=1,hudmake=display
:state=0:hudreset,hudx=50,hudy=50,hudimagefine=gamecore\text\Ultima.bmp,hudname=learnultima,hudhide=1,hudmake=display
:state=0:hudreset,hudx=50,hudy=50,hudimagefine=gamecore\text\LevelUp.bmp,hudname=levelup,hudhide=1,hudmake=display
:state=0:coloff,dimvar=PlrLevel,dimvar=PlrEXP,dimvar=CalcVar,dimvar=CalcVar2,state=99
;Give player damage multiplier based upon player's level
;:ALWAYS:setvar=CalcVar %PlrLevel,subvar=CalcVar 1,divvar=CalcVar 2,addvar=CalcVar 1
:ALWAYS:setvar=CalcVar %PlrLevel,divvar=CalcVar 4
:ALWAYS:mulvar=CalcVar 100,plrdmgmult=%CalcVar
;HUD Upkeep for player's exp bar
:varequal=InvUp 0:hudshow=exp0,hudshow=expbar
:varequal=InvUp 1:hudunshow=exp0,hudunshow=expbar
:ALWAYS:setvar=CalcVar %PlrEXP,setvar=CalcVar2 %PlrLevel,mulvar=CalcVar2 15,divvar=CalcVar %CalcVar2,mulvar=CalcVar 100,scalehudx=expbar %CalcVar
;:ALWAYS:divvar=CalcVar 100,subvar=CalcVar 1,mulvar=CalcVar 20.8008,addvar=CalcVar 50,sethudx=expbar %CalcVar
;Determine if player level'd up
:ALWAYS:setvar=CalcVar %PlrLevel,mulvar=CalcVar 15
:vargreater=PlrEXP %CalcVar:subvar=PlrEXP %CalcVar,state=1
;Player Level UP sequence
:state=1:addvar=PlrLevel 1,plrsound=$0,hudshow=levelup,hudfadeout=levelup,state=2
;Check if Player learned a new Spell
:state=2,varequal=PlrLevel 2:hudshow=learnblizzard,hudfadeout=learnblizzard
:state=2,varequal=PlrLevel 3:hudshow=learnthunder,hudfadeout=learnthunder
:state=2,varequal=PlrLevel 5:hudshow=learnfira,hudfadeout=learnfira
:state=2,varequal=PlrLevel 7:hudshow=learnblizzara,hudfadeout=learnblizzara
:state=2,varequal=PlrLevel 9:hudshow=learnthundara,hudfadeout=learnthundara
:state=2,varequal=PlrLevel 12:hudshow=learnfiraga,hudfadeout=learnfiraga
:state=2,varequal=PlrLevel 15:hudshow=learnblizzaga,hudfadeout=learnblizzaga
:state=2,varequal=PlrLevel 18:hudshow=learnthundaga,hudfadeout=learnthundaga
:state=2,varequal=PlrLevel 21:hudshow=learnultima,hudfadeout=learnultima
:state=2:state=99
Also, for earning EXP, you'll want to give your enemies a destroy script like this one. (This one gives 3 EXP when the enemy dies)
; EXP Destroy - by Plystire
; Requires Ply's Mod V1.07 or Higher
desc = Kill enemy for EXP
;Triggers
:state=0:state=1,addvar=PlrEXP 3
:state=1,alphafadeequal=100:decalphafade=1
:state=1,alphafadeequal=1:state=2,destroy
Enjoy!
The one and only,
