One of the innovations in the d20 rules that was made by the Paizo folks was the Combat Maneuver Bonus/Combat Maneuver Defense scores.
Basically they took all the fiddly 3E combat actions (disarm, trip, bull rush, grapple, etc.) and turned them into this formula:
CMB = BAB + Str + any special bonuses (in other words, a basic attack roll, modified by feats/class abilities).
CMD = 10 + BAB + Str + Dex + any special bonuses.
I'm considering using the basic formula for my Classic D&D games for whenever anyone wants to do something like swinging from chandeliers, flipping their cloak over the opponent's head, throwing sand in their eyes, or the above grapple/disarm/trip type stuff.
I'm already using ascending AC/attack bonus, so this would be easy enough to add in. For monsters, they just get normal attacks, and 10 + HD for CMD (maybe the creatures that get a Strength bonus/penalty to damage could factor that in as well).
Simple, easy, and hopefully will make for more dynamic combats than simply "roll to hit, roll damage, rinse and repeat."
The Old Mage's Almanac - Spells of Voice
36 minutes ago