Type 1:
you are attacked by a level 5 monster. you are a level 3 and have a +1 sword you use a potion to add +3. you win 7 to 5, monster dies.
Type 2:
you attack the monster and do two damage. the monster attacks and does one damage to you. you go until one of you is dead.
Type 3:
your attack + a dice roll vs Monster defense + a dice roll. if you win you do one damage.
Monster attack + a dice roll vs Your defense + a dice roll. if you lose you take one damage.
Type 4:
your attack + a dice vs monster attack + a dice. winner takes one damage.
Type 5:
you have 1 attack. you are up against a slime. the slime has 1 attack and tie goes to the
monster. you use a potion to give you +1 you defeat the slime.
(keep in mind that the dice will not be shown. players will see attack numbers as a range like 3 - 5.)
so I think my favorite one so far is type 4. what do you think. keep in mind I won't be using final fantasy numbers. there is no 9999 damage. I am thinking of never leaving double digits. dice will probably only be +0, +1, +2.
Type 1: I don't like this because it makes it nearly impossible to defeat stronger monsters without boosting your stats incredibly high.
Type 2: BORING, but would work. No strategy element.
Type 3: Only 1 damage? This would also work.
Type 4: Again, only 1 damage? I like type 3 more than this because it takes defense into account instead of it being a useless stat.
Type 5: No. Again, this makes it difficult to defeat monsters higher level than yours.
I'd say the best type would be 3, though you need to have more than one damage. Perhaps both roll a dice based on the 'luck' statistic (Or luck+'ing items). This bonus dice has a number of sides equivalent to your luck statistic divided by 2/3/4/whatever/maybe-another-statistic-of-yours. Of those sides, make some bad ones, with fewer the higher your luck stat is. Roll this dice and then damage accordingly (+10 for good, -10 for bad).