Before I started thinking about using existing rules, I was working on my own. Still may develop them. Not horribly original, but...
Attack = Number of dice thrown when making an attack. Separate stats for melee and missile.
Armour = Target number for dice. Any rolls >= target number are wounds.
Speed = Each character moves d6+Speed stat.
Wounds = how much damage you can take (negative effects at certain points.)
Turn order is determined by a deck of cards. One card for each character or monster. Plus a certain number of "spawn" cards in the deck at any given time. "Spawn" cards deploy either a monster or a treasure at a random location (I have a system for determining location, too.)
When it's your turn, doll your speed dice. That's how many spaces you can move. You can move up to your speed number. Anywhere along the way you can also perform one action: attack, pick up item, drop item, trade items. Opening or closing a door counts as moving one space.
That's the structure. I've also got a basic list of magic items. Like I said, not too original. A lot of simple ideas borrowed from elsewhere. Combat dice would most likely be a d10.
