Let's try this again, but without the barn. No promises, though.
Looking at Prowess from two posts back.
We don't want to adjust weapon damage and the number of attacks. Nor do we want to screw with armor class or hit points. There are plenty of rules that have already been created in old D&D and a lot of new systems that modify these things. My personal feeling is that AD&D works when adapted by the combat system I use.
Regarding that combat system. Sigh. I've tried so many times to express it here on the blog and I think it always misses the mark (here or here). I started writing it out as a rule system, but between the complexity of the system and the limitations of blogs, it never has seemed to get off the ground. Which is funny, since it seems to take two combats for a player to adjust to the system and figure out how to play it. It is very hands on, very adaptable, very open to the player improvising and on the whole very easy to learn. Not that it seems that way here.
I know that the fighter sage abilities and the study of Prowess will mean a lot of time spent putting up combat rules online. But that's what the wiki is for.
So, staying away from the things above, what rules can we create? Lots, actually. First, we have to start with some premises of the AD&D game (which will in some ways apply to most other systems). Grognards can skip this next paragraph:
Combatants meet and we decide if anyone is surprised. We calculate the distance between them, roll initiative, then one side begins resolving combat. Decisions to parley instead of fighting are made, weapons are drawn, potential grenade missiles are pulled out, spells are cast. Combatants approach, they charge, they fall back, they enter melee or they fire missiles. They may attempt to pummel, grapple or overbear. We figure out the number of combatants per defender, make rolls to see which defender the attacker attacks out of those within reach. Frontage, flanks, rear attacks all adjust chance to hit. One side takes damage, morale is rolled, one side flees, the other chooses to pursue or not. This is basically the formula.
Well, there's a lot we can change. Improved initiative, lack of surprise, speed at drawing weapons, using items we usually don't think of as weapons, improved chance of grenade placement or breaking of grenade (spin the oil bottle, it breaks), morale in the face of charges, limiting friendly fire from missiles, employing tools to pummel, adding judo to grappling, improved overbearing regardless of weight, able to reduce number of attackers through defensive stance, number of defenders per hex, removal of penalties for being attacked by one of two flanks, bonus for attacking from flanks/rear (slight AC adjustment there but sensible), improved morale, improved morale of companions, speed of pursuit and movement bonuses for pulling out of combat.
If we can make a rule for it, we can make a rule suspending that rule for fighters with Prowess.
For example, I have a rule that states a character drops a weapon if they roll a 1 on their attack dice. This weapon then breaks on another die depending on the type of weapon (some break more easily than others). This break can sometimes be interpreted as snapping the weapon by wedging it into a stone wall or cracking the wood so that it is useless . . . or it could mean the character flung it into chasm next to the character. In either case, the weapon is considered forever lost to the character.
If, however, the weapon does not break, it still falls out of the character's hand. I rule that a d8 is rolled. A 1-2, it falls in the same hex as the character and it can be easily scooped up the following round. A 3-8 and the weapon has fallen into one of the six hexes surrounding the character, in which case the character must move to go get it. It could fall under the feet of the enemy, where it is considered out of reach unless the enemy can be made to move. Or it could fall into the hex next to the wall where the character is fighting, in which case it falls off the building and is effectively lost. So there are actually two chances for the character to lose the weapon, depending on the circumstances where the fight is taking place. Naturally, there is also the chance the enemy will pick up the weapon and give it to someone else or use it. There's also a chance the enemy will kick the weapon back and away, or off the cliff.
So - Avoid throwing weapon under foot of enemy would be a useful skill to have. So would, Avoid throwing weapon off cliff. These are options the player would like to have. Obviously, we don't want to completely avoid the chance, but throwing a d10 instead of a d8 for where the weapon winds up is easy, right? 1-4 under the character, 5-10 in an adjacent hex. Offering a saving throw to the player if they want to scramble for the sword before it bounces off the cliff; or an option, such as, "Well, you can dive for the sword and save it, but you're AC 10 for the enemy's next swing; your choice."
At least there is a choice. That's all players want. A choice, a chance, a slight edge that adjusts the troubles they're experiencing in their favor. We don't have to go all out and give them three times the damage to make them happy. They'll be happy if they can, just once, stop their favorite weapon from falling off a cliff.