I was playing around with the idea of DMing a dungeon for a single player.
The idea is that the player controls a squad of 4 characters (fighter, cleric, thief, wizard)
The rules are cut down to a dirt simple interpretation, so the (a) the player doesn't have to worry about too much stuff and (b) hopefully the player can get through a small dungeon in a single session.
Simplifications I've Made
You have no ability scores.
HP and Armor are both folded into HP.
(fighters have more HP because they can wear better armor.)
Weapon damage and attack bonus have been folded into Damage.
All attacks hit, but the damage is a bit variable.
Damage is based on class, not weapon type.
Saves, Checks, Combat Manuvers are usually against DC 11.
Usually, you get +0 or +5 to these checks.
-I sorta had tournament-style play in mind when I wrote these.
-These might also be suitable for teaching children or babies or something.
-If you want a better simulation of low-level DnD, cut all the HP totals in half.
-If you want to include miss chances, just say that whenever a damage die rolls max damage, it does no damage instead or something.