I'm in the process of converting "The Barony" (my OSR campaign) from the 5th edition of Tunnels & Trolls to the 1st edition of Dungeons & Dragons (boxed set only, no supplements). While my intent is to largely run rules-as-written, there is always room for house rules!
One area where T&T is superior to (original) D&D is the use of stat checks. It's baked into the very core of T&T, yet it doesn't show up in D&D until much later. oD&D seems to ignore the stats for the most part, but some things beg for a stat check:
Player: Can I push that heavy crate?
GM: Make a Strength roll!
Player: Can I seduce the princess?
DM: Make a Charisma roll!
In T&T you make a stat check by rolling 2d6 and adding your stat. You try to get 20 or better for a simple task, 25 or better for a difficult tasks, or 30 or better for a very difficult task. These "impossible" rolls are made possible because T&T was the first RPG with an "exploding dice" mechanic (the same exploding dice mechanic found in board game Monopoly: go again on doubles).
In original D&D, it's never mentioned anywhere, rather they have a strange saving throw mechanic that I see people use for some of those situations. As far as I can tell, the Ability Check doesn't make an appearance in a D&D rulebook until the 1991!
One game where the stat check works better than either T&T or D&D is GURPS, but in GURPS you have to roll low, and I don't like that.
The game with the best stat check mechanic is Fudge. So I am lifting Fudge's system and applying it to oD&D. I imagine some old school purists will hate the use of such a modern mechanic to such an old game, but I think it will work well in play.
How it Works
For each of the 6 stats, in addition to the number, the character sheet will also have a space for an adjective. The adjective will be based on the stat level as follows:
Then whenever the player wants his character to attempt to do something, it's very easy for me as the DM to come up with the "target adjective". So if the player says "I want to push that heavy crate" I can say "It's only a little heavy, so even a Mediocre Strength check will do" or "It's really heavy, so you need a Good strength check" or even "But you're trying to push it up a steep, uneven ramp! You're going to need a Superb Strength check!"
The stat check itself is a normal Fudge roll: roll 4dF and slide the attribute up or down as indicated by the dice.
New school stat checks on an old school game. Easy peasy lemon squeezy!