Monk, a class for old school D&D
HP, XP, Attack Bonus, and Saving Throws as cleric. In LotFP, monks receive the non-fighter attack bonus, but only suffer a -2 penalty to attack rolls or AC when they Press or Parry. They also learn two Techniques of their choice and invention (and Referee's approval) every level.
Techniques allows monks to recreate the effects of a particular weapon or armor their bare hands. A monk who has mastered the Hundredweight Hand (Battleaxe) technique can chop lumber, bash through doors, and deal battleaxe damage just with the edges of their hands.
Techniques bring all the advantages and disadvantages of the weapon or armor, so if it mimics a two-handed weapon, a technique requires two free hands. If a technique mimics plate armor, the monk must move as slowly as if they were in heavy armor to maintain the effect. Also, armor-based techniques require the monk to limber up for as long as it would take to don armor of the same AC.
All techniques must be be justifiable fictionally. A monk with the Heron Fist (Spear) technique could use it to probe for traps (as someone with an actual spear might) and claim to avoid the pitfall or whatever by virtue of the technique's speed. But they couldn't use it to hook the guard's keys off her belt from far away.
Oh, and players get to make up names for their techniques.
I'd suggest being generous for techniques that are odd/interesting/useful in non-obvious ways and conservative with techniques that are very powerful and direct (e.g. a technique based on heavy artillery). Here are a few weirder possibilities for starters:
- Heavenly Kick (javelin): The monk can jump as far as they can throw a javelin, dealing damage to whatever they kick/land on.
- Pure Flame Technique (torch): The monk's punch deals d6 fire damage and ignites anything flammable
- Bone Cage Technique (net): struck enemy counts as heavily encumbered until they take an action to steady themselves.
- Armor Peeler (gun): Ignores AC bonus from armor. Only usable in melee range.
- Blessed Palm (holy water): counts as holy water for damage (so it deals 0 damage against regular creatures and harm undead). Only usable in melee range.
- Cursed Fist (magic weapon): Counts as a magic weapon for purposes of damage immunity and reduction.
- Empty Hand Shield (shield): +1 AC as long as the monk keeps one hand free
So ideally you have an unarmed and unarmored warrior encouraged to use a combination of lateral thinking and direct confrontation in their fights, with enough weird talents that they can be of use in that crazy heist the party has just planned.