Three-dimensional growth and thieves

 As I've mentioned before, mages gets better in three "dimensions" as they level up.

- They get more spells.

- They get better spells.

- The spells they already have (e. g., magic missile) become more powerful.

To do something similar, the fighters need:

- Better attacks (i.e., bigger "to-hit" bonus).

- More attacks.

- The attacks get better (i.e., more damage per attack).

Not hard to do at all, especially if they get magic swords and other weapons.

(Although these things are not exactly the same - spells can attack and open doors and deceive and carry stuff, while attacks can only attack. OTOH spells are limited by spell slots while attacks are not, although the MU gets more slots as he levels).

But what about thieves? I guess they should get:

- More skills.

- Better skills.

- Improve the skills they already have.

This is a bit harder to do. 

The B/X thief gets better at their skills. They do get a couple of extra skills as they level up (reading languages and casting from scrolls - which don't get better), but these are rare (the MU gets new spells every level).

Giving thieves "skill points" like LotFP is helpful - now they can distribute them freely between "new skill" and "get better at skills you have" (well, to be precise, they don't really get new skills, since every skill starts with a 1-in-6 chance, but... it could be done if you add new skills to the game that you can only access through "points").

Still, while you get better chances of success, your successes are always the same. 

So, you get better chances of hiding or climbing - but you don't usually get to hide more people nor do you climb faster as you level up. You open locks more often, but not any faster, etc.

This is "fixed" in modern versions of D&D, but not B/X or AD&D.

One easy way to change that is adding "critical successes" of some kind for thieves' talents.

For example:

If you're using 1d100, "doubles" are now criticals. For example, if you can climb twice the distance or at twice the usual speed, and if you hide you can attack once and remain undetected.

Conversely, you could just add modifiers to these skills. "Attack and hide" imposes a -30% penalty, for example.

Even better, you could use some kind of synergy for thief skills, allowing some skills to affect others.

Single attack/damage roll (kubular), but divided in half

I think I discussed that idea at the time, but I didn't write down this exact implementation. Read that post before this one! This method has several advantages over the usual D&D method.

Here is the deal: no more damage rolls.

Just roll 1d20 plus modifiers and subtract AC, then divide by two: this is the total damage (minimum 1).

Modifiers include attack bonus and weapon rating (WR).

WR usually goes from -3 (unarmed) to +3 (heavy 2H-weapon).

A dagger has +0 WR; other weapon are easy to figure out (d6, d8 and d10 become +1, +2, +3).

Improvised weapons, gauntlets, etc, have a WR of -1 or -2.

Lets assume ascending unarmored AC 11 (like BFRPG).

A dagger hit deals an average of 3 damage against unarmored targets, a bit over the original (nice!).

A 2H-sword, OTOH, deals 3.77 damage on a hit, but hits more often than in the original BFRPG; the DPR (damage per round) is about 2.45, a bit HIGHER than the usual 2.25.

What about heavy armor? Say, Plate mail is AC 17 in BFRPG. 

To hurt someone in plate with bare hands, you need a natural 20 (realistically, you'd be more likely to hurt your hand... add some grappling rules to your game!).

A dagger will only deal 1.5 points of damage. 

A 2H sword deals an average of 2.5 damage (originally 4.5), but again the DPR is 0.8, not far form the original (0.9).

I'd definitely combine it with some "armor defeating" rules for maximum effect. E.g., cutting weapons deal 1 point of additional damage if they hit, maces get +2 to-hit against chain or heavier, axes are +1 against everybody, etc.