One of the limitations of old school Rules Cyclopedia D&D is the way it treats demi-humans. It’s both restrictive, and tough, with a clear human-bias. Elves can’t be clerics, just fighter/magic-users. Dwarves are stocky fighters with infravision. It’s interesting from the “being creative within these tight restrictive guidelines” but sometimes you want to push out beyond that.
For example, my wizard in my 5e game is a battle ax swinging, chainmail shirt wearing, dwarf with impulse control issues. Kinda hard to pull that off as a PC in RC D&D.
However… as an NPC/monster? Totally doable! It’s basically just a handwavium deal!
Fulhoff, Dwarf Wizard, level 4
Armor Class: 5
Hit Dice: 4d4+8**** (18hp)
Move: 90' (30')
Attacks: War Hammer or Spell
Damage: 1d8+2 or per spell
Save As: W4
Treasure Type: C (plus spellbook)
XP Value: 425
Fulhoff is smart, but foolhardy, and just as likely to charge into battle with his hammer as he is to use his magic. He's come close to death a few times already, and is beginning to learn a little more self control.
1: Thunderwave, Witchbolt, Charm Person, Shield
2: Invisibility, Mirror Image