Birth feats are little nuances that change how your party will be placed in terms of strengths and weaknesses.  It is not something you need to worry about too much on first playthrough (and I generally recommend the default party for that), but once you want to explore the many different ways in which Dungeons of Chaos can be enjoyed, playing around with feats is one key element.

Feats in general can be described in 4 parts:

  • what classes can take them
  • what benefits do they bring (usually mysteriously described as a “+” or “++”. Exact bonus is NOT revealed but “++” is better than “+”)
  • what downside do they come with (“–” is worse than “-“)
  • how rare it is to appear in a random roll

4 feats are showing with each roll.  They may not suit the class you want to pick at all, so it is also perfectly common to have a player without a birth feat.  But many people try to roll a specific target character.  If the feat is rare, they would roll until it shows up and then see if they can live with the stat roll.  If stats are more important, they focus on good stats and then see if the feats are ok.

Without further ado, here they are in the order of rarity (below is per v1.9.30 which added 5 new ones):

PHYSIQUE [most common]
CLASSES ALLOWED:  fighter, barbarian, ranger, archer, rogue, monk, druid
NOT ALLOWED:  cleric, mage
BONUS:  Str+, Dex+, Health+
A no-nonsense boost to the most basic stats.  Can make the difference on whether you can equip that piece of armor or weapon you have been eyeballing.

CLASSES ALLOWED:  fighter, barbarian, ranger, monk, cleric, druid
NOT ALLOWED:  archer, rogue, mage
BONUS:  Str+, Health++, Resist Cold+ Poison+ Stoning+, Gold+, Gear (Depends on class chosen: Axe, Hammer, Shield …), Harden Up Skill+
DOWNSIDE:  Speed-, Mana-
Clearly a good set of features for a melee character or even monk or druid.

NOBLE ORIGIN [very common]
CLASSES ALLOWED:  fighter, archer, ranger, cleric, mage
NOT ALLOWED:  barbarian, rogue, monk, druid
BONUS:  Gold+++, Gear (Depends on class chosen: nice helms or enchanted jewelry…)
Not powerful in the long run but a good starting boost if you want to be well equipped from the go get, or to stock up in store right away.

TOUGHNESS [very common]
CLASSES ALLOWED:  fighter, barbarian, ranger, archer, rogue, monk, druid
NOT ALLOWED:  cleric, mage
BONUS:  Resist Fire++ Cold++ Lightning++
May not be your obvious choice initially but in certain stages of the game you may want to have someone that can withstand a fistfight with enemies dealing elemental damage (and lots of it).

CLASSES ALLOWED:  fighter, archer, ranger, rogue, monk, cleric, mage, druid
NOT ALLOWED:  barbarian
BONUS:  Dex+, Speed+, Evasion+, Mana+
DOWNSIDE:  Health-
Nothing terribly exciting but an overall good net benefit for any spellcaster, ranger or rogue

MENACE [common]
CLASSES ALLOWED:  fighter, barbarian
NOT ALLOWED:  archer, ranger, rogue, monk, cleric, mage, druid
BONUS:  Rage Skill ++
You REALLY get into the mood for battle.  Deep into it…

BONUS:  Weapon proficiency ++
Tailored to include those weapon types common for the class (including unarmed for monks), this feat gives you a good boost to those skills, with all its benefits (more advanced weapon attack styles, and better accuracy).

INTELLECT [common]
CLASSES ALLOWED:  archer, ranger, rogue, monk, cleric, mage, druid
NOT ALLOWED:  barbarian, fighter
BONUS:  Mana++, Perception Skill+, Identify Skill+
Can’t go wrong with this for a spellcaster, the extra skills help with out of combat non-magical stuff as well like finding treasures or spotting monsters when resting.

CLASSES ALLOWED:  fighter, barbarian, ranger, monk, druid
NOT ALLOWED:  archer, rogue, cleric, mage
BONUS:  Str+, Health+, Resist Fire+ Cold+++ Poison+++ Stoning++ Sleep++, Harden Up Skill+, Rage Skill+
Not what you would like to see in a mirror, but on a stats sheet of your fighters this is quite pleasing.

PROTEGE [uncommon]
BONUS:  Whatever spell and skill level (or access at all) your class usually gets at level ~5, you have it from the start
Weapon skills, cooldown skills, daily skills, resist and attack spells … if a skill or spell is useful, why not have more proficiency in it?  I call this the most underrated feat based on player feedback to date.  Probably because it does not come with ground braking changes or cinematics.  It is just as if you had been grinding for a bit.

IMMUNITY [uncommon]
BONUS:  Resist Poison ++++
In some situations you may think this is useless.  In others, it is the difference between life and certain death.

SUREHANDED [uncommon]
CLASSES ALLOWED:  fighter, ranger, archer, rogue, monk
NOT ALLOWED:  barbarian, cleric, mage, druid
BONUS:  Critical Hit Chance ++
Having been blessed with a sense for battle as well as a keen mind for anatomy, you make your hits count (read: HURT).  Some classes lack one of the two though so can’t use this feat.

ANTINODE [uncommon]
CLASSES ALLOWED:  fighter, barbarian, ranger, archer, rogue, monk
NOT ALLOWED:  cleric, mage, druid
BONUS:  Resist Magic+++
If you REALLY hate everything about magic, would rather not use it yourself, and not take too much damage if it is thrown at you, then this is right up your alley.

BODY CONTROL [uncommon]
BONUS:  Resist Sleep+++ Paralysis+++
Arguably SLEEP condition is not yet implemented, however PARALYSIS would always be the more important factor of the two.  Paralysis can make you be inactive during significant portions of a fight without you actually realising that it is those instances of forced inactivity that makes you lose the fight over and over again.  Spectres are one of the creatures that really use this a lot.

TREE HUGGER [uncommon]
BONUS:  Nature Ally skill ++
DOWNSIDE:  cannot use the shoe or jewelry equipment slots
Nature Ally is a nice skill to have early in the game, it can if successful make one or more wolves appear.  Chance of failure reduces with level, and wolf count increases.  At high level it is also rumored to summon a more fierce nature ally.  Can help a lot with low level fights at the start, but also provide a valuable distraction in later fights to throw in some wolves and chew on the back rank spellcaster type mobs that otherwise take too much time to reach and silence.

BLACK SHEEP [uncommon]
NOT ALLOWED:  fighter, barbarian, ranger, archer, monk, cleric, mage, druid
BONUS:  Shadow Shift Skill ++
Some are born into a career of walking the shadows.  And with enough experience, you find that all shadows are connected… shadow shift is a short range teleportation skill that goes from one entity’s adjacent tile to another entity’s adjacent tile.

SWIFTNESS [uncommon]
BONUS:  Speed++, Evade+
A clear benefit to those that want to do something quick so they can either deal more damage over time or get out of harms way.

BONUS:  does what it says on the tin: you get a piece of armor that is quite valuable and its enchantment/stats are specifically useful for your class
Not uber-powerful but a good and safe way to pick something that can make a starting difference without causing issues elsewhere.

BONUS:  does what it says on the tin: you get a ring or amulet that is quite valuable and its enchantment is specifically useful for your class
Not uber-powerful but a good and safe way to pick something that can make a starting difference without causing issues elsewhere.

NERD [uncommon]
CLASSES ALLOWED:  ranger, archer, monk, rogue, cleric, mage, druid
NOT ALLOWED:  fighter, barbarian
BONUS:  Identify Skill++++ (and has seen each item type at least 10 times)
DOWNSIDE: STR-, Evasion-
Saves money and saves having to wait to use (potentially) cool items you find.

STONE SKIN [uncommon]
BONUS:  Armor vs pierce+++ force++ slice++
DOWNSIDE: Speed-, Evasion–
Born with a visually displeasing skin condition that also makes movement a bit harder, you soon found that it is quite suitable in combat as you don’t take as serious a wound as others with normal skin.  Helps most against piercing damage, less so against force damage.

CLASSES ALLOWED:  fighter,archer, ranger, monk, cleric, mage, druid
NOT ALLOWED:  barbarian, rogue
BONUS:  Vs. undead damage bonus of 40-50%, and clerics or monks also get a proficiency (1) in exorcism skill
If you happen to curse a lot under your breath when fighting the lich or spectres, maybe give this a try.

CLASSES ALLOWED:  fighter, monk, rogue, druid
NOT ALLOWED:  barbarian, ranger, archer, cleric, mage
BONUS:   Dex+, Evasion+, Skill Identify+ Sneaking+ Endure Elements+ Taunt+ Nimble+ Lock Picking+
DOWNSIDE:  Health–, STR–
Halflings are not the best at anything particular, but have a clear tendency to be good at nifty things without being as squishy as gnomes are.

TROLL ANCESTRY [very rare]
CLASSES ALLOWED:  fighter, barbarian, druid
NOT ALLOWED:  ranger, archer, rogue, monk, cleric, mage
BONUS:   STR+++, Health++, Health regeneration+++
DOWNSIDE:  Mana–, DEX–, Speed–, Evasion–
Trolls are great for bashing skulls in and regenerating their own wounds on the fly.  Really great.  Anything else? Not so much.

NODEMASTER [very rare]
CLASSES ALLOWED:  monk, cleric, mage, druid
NOT ALLOWED:  fighter, barbarian, ranger, archer, rogue
BONUS:   Mana regeneration+++
DOWNSIDE:  Speed-, Evasion-, Lower Poison Resist (inherent and endure element stat is halved.  Item bonus still works)
Not much is known about the origins of magical powers really.  Some characters are way better at replenishing their mana reserves than others.  It is less noticeable that they also tend to suffer from a slight sluggishness, and are very vulnerable to poison.

DYNAMO [very rare]
BONUS:   Lightning Damage added to your attack.  Strongest for unarmed, normal for melee, and small for ranged weapons.  Scales up with your player level.
DOWNSIDE:  Resist Magic— (inherent player stat is set to ZERO.  Item bonus still works)
A mystery why some have this ability, at their will they can deal lightning damage as part of their melee attack.  For ranged attacks, they charge static electricity onto their ammunition for at least a smaller version of it.  The powers that enable this ability unfortunately seem to make the person very vulnerable to magic damage.

GNOME ANCESTRY [very rare]
CLASSES ALLOWED:  monk, rogue, druid
NOT ALLOWED:  fighter, barbarian, ranger, archer, cleric, mage
BONUS:   Dex++, Evasion++, Speed++, Skill Identify++ Sneaking++ Perception++ Nimble++ Lock Picking++
DOWNSIDE:  Health—, STR—
Gnomes can be a perfect accompaniment (if you ever come across one that wants to join you) if you need some locks picked or things found.  But you really need to shelter them in battle as they can’t take too many hits.

NOT ALLOWED:  fighter, barbarian, ranger, archer, monk, cleric, mage, druid
BONUS:   Backstab Skill+, Evasion++
DOWNSIDE:  Accuracy—-, cannot wear rings or amulets
A very specific breed of rogues.  Trumps others in backstab and evasion, and his taunt can make even a seasoned enemy stray from their expertise tactics, but in the end he sucks at pretty much everything else.

CARRIE [very very rare]
CLASSES ALLOWED:  mage, druid
NOT ALLOWED:  fighter, barbarian, ranger, archer, monk, rogue, cleric
BONUS:   IGNITE Spell+++, Mana++
DOWNSIDE:  Speed—-
A rare to find one-trick pony.  But what a fiery trick it is… if you can live with the super slow speed they have.

FROST HANDS [very very rare]
BONUS:   Cold Damage and a small freeze effect is added to your unarmed attacks.  Does not apply when you use a weapon.  Scales with your level.
DOWNSIDE:  DEX–, cannot wear gloves, Resist Fire— (inherent player stat is set to ZERO.  Item bonus still works)
Not many people have ever seen this.  The hands are deformed but have an inner blue glow…

The following feats are unlockable in 1.9.90 onwards (ETA 22 November 2016) via certain late-game achievements:

BLOOD LUST [uncommon]
BONUS:  Lifesteal: a % of damage heals you (7% unarmed,  5% melee, 3% ranged), Life Drain Damage ++
DOWNSIDE:  Evasion—-, No vs. undead bonus. Ever.
Those that are on the brink of vampirism have clear benefits in combat, if it weren’t for the fact that their reaction time is very slow.  Or may it is their cockiness that comes with being one step closer to perceived immortality… And neither items nor spells nor skills can grant them any bonus vs. undead.

DRAGON BLOOD [uncommon]
BONUS:  Summon dragon skill +, Health++, Health regeneration+
DOWNSIDE:  Resist Cold— (inherent player stat is set to ZERO.  Item bonus still works)
Clearly boasting with health, those that have somehow been granted a little favour of Zomok just have to deal with a tiny inconvenience of NIL cold resistance (before item bonuses).  The temptation is of course there to reach out to Zomok and plead for help once in a while.  Zomok may do nothing.  Or he may send you a dragon as an ally during combat.  Or you may catch him in a bad mood, and a dragon appears in the enemies’ ranks… and don’t even ask what he will do if you dare to ask twice in the same fight (which is by the way only possible if you have two players with the skill).