Level limits! Class limits! Who loves them? Here’s my take – they’re a powerful tool for world-building and in determining the power balance of a setting. If only humans can be archmages, if halflings can’t rise above 6th level as fighters, or if dwarves can’t be clerics or wizards, that tells you a great deal about what your gameworld is like.

So what if you don’t want this?

You can easily just remove class and level limits – allow any race to attain any level in any class. This is the norm in more recent editions of the game. In AD&D, though, you could argue that this short-changes humans. So one way to compensate is to give humans a boost.

When I run AD&D 2nd Edition, that’s the approach I take. Specifically, humans receive a +1 bonus to any one ability score, and can choose two special traits that reflect where in the world they’re from – sort of like mini-feats. I originally took this idea from issue #315 of Dragon magazine, where they presented regional feats for characters from the excellent World of Greyhawk. Here’s what it looks like for my current Dark Sun game:

Humans

Ability Adjustments: +1 to any one ability.
Movement Rate: 12.
Background Traits: Humans receive two background traits from the following list. These traits should reflect the human’s origin or culture.

Human Background Traits

Arcane Affinity: Targets of your spells suffer a –1 penalty to their saving throws.
Arcane Heritage: Magic is in your blood. Select one saving throw category and apply a +1 bonus to it.
Alien Mind: Your thoughts are strange and unpredictable. You have 10% magic resistance against all spells that attempt to read your mind.
Aptitude: Choose one ability score. Whenever you make an ability check with this score, roll two dice and pick the best result.
Artisan: You receive a +2 bonus on all craft non-weapon proficiency checks.
Bareback Rider: You suffer no penalties when riding bareback. You can guide your mount with your knees, keeping both hands free. You gain a +1 bonus to hit when using a ranged weapon while riding bareback.
Bullheaded: You receive a +1 bonus on saving throws against mind-affecting effects and a +2 bonus on intimidation non-weapon proficiency checks.
Child of the Ringing Mountains: You suffer no movement penalty in mountains or forest.
Cold Resistance: You receive a +1 bonus on saving throws against cold-based effects.
Combat Training: You gain a bonus weapon proficiency.
Commander: Your hirelings and henchmen gain +2 to morale.
Cosmopolitan: Select a race other than human. All members of that race are automatically Friendly towards you when you first encounter them.
Desert-Born: You are immune to damage from heat stroke and exposure to the cold.
Elfblood: You gain 30’ infravision.
Expert Rider: Choose a mount type. Gain +2 on all non-weapon proficiency checks relating to riding this mount type. All such mounts are Friendly towards you.
Faithful: You may use your Will Bonus instead of your Stamina Bonus to determine your bonus hit points.
Foe Hunter: Select one race and receive a +1 bonus on damage against them.
Heat Resistance: You receive a +1 bonus on saving throws against heat and fire-based effects.
Lucky: Reroll one failed saving throw per day.
Mental Fortitude: You may use your Insight Bonus instead of your Stamina Bonus to determine bonus hit points.
Mercantile Expertise: Make a successful Charisma check to buy equipment at a 10% discount. You can help others get this discount. When selling, a successful Charisma check grants you 10% more in the sale.
Pathfinder: You are skilled at navigation and never become lost when travelling in the wilderness.
Raider: You gain a +1 bonus on saves vs. fear and a +2 on observation non-weapon proficiency checks.
Reduced Water: You need half as much water each day as normal.
Rustic Charm: All urban folk start out as Friendly, You receive a +2 bonus on all reaction checks.
Self-Sufficient: You gain a +2 bonus to survival non-weapon proficiency checks made in one type of terrain.
Silt Diver: You can hold your breath for half your Constitution score in rounds.
Skilled: You gain a bonus non-weapon proficiency.
Spirit Sight: You can see incorporeal or ethereal creatures on a successful Wisdom check.
Tough: You gain +1 hp per level.
Well-Trained: You receive a –1 bonus on all initiative checks.
Worldly Charm: You receive a +2 reaction bonus when meeting new people and a +1 bonus to etiquette non-weapon proficiency checks.

As a bonus, included in the attached pdf are the rest of the standard Dark Sun races, so you can see how humans compare to them side-by-side.