Need input on equation

I'm having trouble trying to make a formula that would be good for my RPG game.

I have 3 main stats:

Guts: For User's Life, for attack strength (Critical Hit... ect)

Wisdom: For Skill mod, and for magic strength (+ damage mod)

Chrisma: See how much you could trade or if trade possible. Also for theif skills.


and then I have 3 supporting such as Attack, Defense, and skill.

With Items such as a Short Sword that (has and attack + 5 , Defence + 0 , and Skill + 2) that would +/- the user's Supporting SKill.

While the character has these, also the bad guys have them too.

I was wondering how I could make a Attack Formula that would be a average attack such as...

Jacob has 18 Guts, 12 Wis, 10 Chr... He attacks using a short sword and his stats are (5 attack, 4 def, and 8 skill) while the orc he is battling has 22 Guts, 8 Wis, 8 Chr armed with stats of 8 attack, 6 def, 4 skill...


The battle starts! But where to begin... any idea's?

Lets see...

Need's a Random Attack roll such as 1 to 50 ?

Base Attack = (Char.Wis) - ( Mon.Wis)

roll = int(rnd*50)+Base Attack

Select Case Roll


Case =< 5
'Miss: Creature Dodges, Deflects Blow... ect ect

Case 6 to 35
'Normal hit...

Case 36 to 45
'Potent Hit, damage mod + int(rnd*5)+5

Case >=46
'Critical hit, damage mod + int(rnd*10)+10

End Select...


Damage?

Begin with: Mon.life = Mon.Guts

(Mon.life) = round((Mon.life) - ((Char.Attack + Damage.Mod) / 2))

... Or would that be to hard for players to attack and kill the monsters or would it be to easy ?