Anti-Feats (PEACH!)

[Crisis21]

Well, here it is, the Anti-Feat list I've been working on for a while. Finally got it sorted and at a decent length. What follows is 28 individual and distinct Anti-Feats (with two that you can take for any of the six main ability scores, so they probably count as 6 each for 38 different possible Anti-Feats).

The goal here was to try and balance these both in flavor and against actual Feats in the game already (please, let me know how well I've succeeded or not, I beg you!). More than that, the goal was to make trading Anti-Feats for Feats (on a one-to-one basis) a net loss for the character, where they always lose just a bit more from the Anti-Feat than they would gain from the bonus Feat.

As always, Please Evaluate And Comment Honestly!



Anti-Feats (Flaws):

Anti-Feats (Flaws) are significant holes in an adventurer's abilities. They represent a weakness that your character must deal with that could prevent them from being a successful adventurer. If the DM allows, you may select one at character creation and in exchange gain a bonus Feat to offset the disadvantage. If there are any prerequisites to an Anti-Feat, then you must fulfill them before taking the Anti-Feat. In addition, the Anti-Feat itself will prevent you from fulfilling conditions that would make you ineligible for it.
To buy off an Anti-Feat, you must arrange it with your DM at least one level before you would gain an Ability Score Increase and roleplay any necessary actions to try and counter the Anti-Feat's effects. Then, the next time you would gain an Ability Score Increase through leveling up, you may forego it and remove the Anti-Feat instead.


Anti-Feat: Absent-Minded

Let's face it, you really would forget your head if it wasn't attached.
You have -1 to Intelligence.
You have disadvantage on Intelligence checks, saving throws, and concentration checks.


Anti-Feat: Anosmia

Prerequisite: Member of a race that can be poisoned.
You have lost your sense of smell.
You automatically fail any Action or ability check requiring a sense of smell.
You have disadvantage on ability checks using Cooking Utensils and Alchemist's Supplies.
You cannot identify poison or disease unless the concentration is sufficient that it leaves visible traces.
You have disadvantage on saving throws versus poison.


Anti-Feat: Bad Arm

One of your arms doesn't work quite right. You might have been born that way or you might have had a broken arm earlier in life that never healed right. Your bad arm is not considered your dominant arm.
You have -1 to Dexterity or Strength.
You may not hold any weapon in that hand that doesn't possess the Light property.
You may not wield any two-handed weapon with the Heavy property.
Attack rolls made using that arm are done with disadvantage.
You have disadvantage on all Strength (Athletics) and Dexterity (Acrobatics) checks requiring use of your arm.
If you use a shield on your bad arm, it only grants +1 AC instead of +2.
Your dead lift capacity is reduced to your maximum encumbrance.
Whenever you cast a spell with a somatic component, roll a d4. On a 1, you flub the somatic component and the spell fails.


Anti-Feat: Blind

You are completely blind.
You automatically fail any Action or ability check requiring sight.
You cannot make ranged attacks.
You have disadvantage on all melee Attack rolls.
You may choose to take the Rogue class's Blindsense ability (if you are able to hear, you are aware of the location of any hidden or Invisible creature within 10 feet of you) as your bonus Feat in exchange for this Anti-Feat. If you do, you no longer have disadvantage on melee Attack rolls as long as you can hear and you may use your hearing for class features that specify something 'you can see'.


Anti-Feat: Bum Leg

Prerequisite: No levels in Monk.
One of your legs doesn't quite work right. You might have been born that way or you might have had a broken leg earlier in life that never healed right.
You have -1 to Dexterity or Strength.
Your movement speed drops by 5.
You have disadvantage on all Strength (Athletics) and Dexterity (Acrobatics) checks requiring use of your bum leg.
Your carrying capacity is halved.


Anti-Feat: Deaf

You are completely deaf.
You automatically fail any Action or ability check requiring hearing.
You have disadvantage on Dexterity (Stealth) checks.
If an enemy you cannot see attacks you, it is considered a surprise attack.
Unless you possess the Observant Feat or some other feature allowing you to read lips, you cannot understand spoken language at all.
Note: You do not automatically know any form of Sign Language unless you gained it through a bonus Language from your background or another source.


Anti-Feat: Disability

Choose one ability score. You have -2 to that ability score.
Your new maximum value in that score is now 14 and your total in that score may no longer exceed 14 for any reason, including magic. (If for some reason, your natural score in that ability is still over 14, such as at character creation and/or random selection of flaws, redistribute any excess points to other abilities until it equals 14)


Anti-Feat: Foolish

If there's a sensible course of action… you probably aren't using it.
You have -1 to Wisdom.
You have disadvantage on Wisdom checks and saving throws.


Anti-Feat: Hemophiliac

You have a dangerous condition for an adventurer. If you start bleeding, you simply don't stop unless you receive healing.
If you take any bludgeoning, slashing, or piercing damage you begin bleeding uncontrollably. You take 1d4 bleeding damage each round for each bludgeoning, slashing, and/or piercing wound you have suffered.
Stopping the bleeding requires either magical healing (you may stop 1d4 bleeding damage for every 5 points of magical healing you receive) or using a Healing Kit and a successful Medicine check made at DC 20.
All bleeding stops if at any point you are restored to full hp.


Anti-Feat: Illiterate

Prerequisite: No levels in Wizard.
You never learned to read as a child and at this stage in your life, you really don't see the point of learning.
You have -1 to Intelligence.
You are incapable of reading any language, including those you can speak. You automatically fail at any Action or other activity that requires you to read.
You cannot use any scrolls or other form of written magic.


Anti-Feat: Inept

Prerequisite: No levels in Bard.
You are highly unskilled. Heck, you are outright hopeless at many tasks.
Choose three Skills you have proficiency in. You are no longer proficient in them.
You subtract one third your proficiency bonus (rounded up) from any ability check where you do not add your proficiency.
You do not qualify for any Feat that would grant or improve proficiency in any Tool or Skill.


Anti-Feat: Klutz

You are pretty darn clumsy, and you have actually tripped over thin air more than once. People who know you try to avoid standing anywhere you could crash into them.
You have -1 to Dexterity.
You have disadvantage on Dexterity checks and saving throws.


Anti-Feat: Monolingual

You never learned another language other than your race's native tongue.
You have -1 to Charisma or Intelligence.
If you are human, you know either Common or whatever regional language your DM declares is spoken where you grew up.
If you are any other race, you know your race's primary language (whichever option on your racial language feature isn't Common).
If you are a half breed race, you must choose one half of your heritage to know your single language from.
You cannot speak, read, or learn any other language and are ineligible for any Feats or features that would allow you to do so.


Anti-Feat: Mute

You cannot speak at all and must communicate with gestures or written language.
You may not attempt any form of Charisma (Persuasion) or Charisma (Deception) check unless you can somehow make yourself understood to the other person.
You have disadvantage on any Charisma check where speaking would significantly improve your chances of success.
You may not cast any spell with a verbal component.
Note: You do not automatically know any form of Sign Language unless you gained it through a bonus Language from your background or another source.


Anti-Feat: Numb


For some strange reason, you do not have a sense of touch. This extends to your sense of taste. You cannot feel pain at all, and often suffer more injury than you think and even injure yourself without realizing it.
You automatically fail any Action or ability check requiring a sense of touch or a sense of taste.
You have disadvantage on all Wisdom (Perception) and Intelligence (Investigation) checks involving physical contact.
You have disadvantage on all Tool checks.
You have disadvantage on saving throws versus Exhaustion and Death saving throws.
You are immune to pain. You cannot be directly tortured or take damage from illusions.
You have advantage on concentration checks while above half health.
If you are attacked and damaged by a creature hidden from you, you are not made aware of their location or even their existence unless someone else is able to point them out to you. If this happens during the surprise round, then your attacker retains surprise. In any case, the DM is under no obligation to tell you you have taken damage or how much until you notice your wounds (DC 15 Perception check), are made aware of them by another, or the DM thinks you might have been killed by the damage.
When you are below half health, you take 1d10 worth of damage any time you take an action, bonus action, or reaction as you aggravate your injuries.
If you undertake strenuous action, such as exceeding your normal carrying capacity or lifting heavy objects, you must make a DC 15 Strength saving throw or take 1d10 damage from overstressing your body. This includes any attempt to escape being grappled.


Anti-Feat: One Arm

You lost an arm at some point in your life and have lived with it ever since. Your remaining arm is considered your dominant arm for all game purposes.
You have disadvantage on all ability checks that would normally require two hands.
You may not wield any two-handed weapons nor use the increased damage for Versatile weapons that would come from wielding them in two hands.
You may not carry a shield while wielding a weapon.
You may not Attack using a bonus action and are ineligible for all two-handed and two-weapon/dual-wielding Feats and features.


Anti-Feat: One Eye

You lost an eye at some point in your life, and probably cover it with an eyepatch.
You have -1 to Wisdom or Charisma.
You have disadvantage on ranged attacks.
You have disadvantage on Wisdom (Perception) checks on your blind side.


Anti-Feat: One Leg

You lost a leg. You may have a crude prosthetic in place, such as a peg leg, or carry a crutch to move around, but you have trouble moving around regardless.
You may not take the Dash action for any reason.
Normal terrain is considered difficult terrain for you and you suffer double the penalty (i.e. half movement speed becomes quarter movement speed) on standard difficult terrain.
You are ineligible for any Feat that would increase your walking speed.


Anti-Feat: Pariah

Maybe you're ugly or maybe you just have a bad reputation. Whatever the reason, people just generally don't like you. Many are hostile, few will tolerate your presence for any length of time, and even fewer are inclined to actually like you.
Ordinary people are likely to attack you if you are not accompanied by a party member capable of dissuading them from the action. If you retaliate for any reason, you will become an immediate outlaw and likely have a mob after you.
You have -1 to Charisma.
You automatically fail all Charisma (Persuasion) and Charisma (Performance) checks and have disadvantage on Charisma (Deception) and Charisma (Intimidation) checks involving any character that is inclined to be hostile to you because of your status.
You have disadvantage on using the Disguise Kit in any area where your status is known.


Anti-Feat: Phobia

You have a severe phobia of a common phenomenon (heights, enclosed spaces, running water, the dark, etc.) or creature (spiders, rabbits, dogs, cats, birds, etc.).
You have -1 to Wisdom.
When exposed to your phobia for any reason, you must make a Wisdom saving throw or be affected by the Fear condition. This fear is not magical in any way and thus cannot be negated by class abilities that protect against fear. In addition, you may never have advantage on an ability check or saving throw involving your phobia.


Anti-Feat: Scrawny

You are the runt of the litter. The skinny kid all the bullies picked on. Pick a name, you've probably been called it by those bigger and stronger than you.
You have -1 to Strength.
You have disadvantage on Strength checks and saving throws.
You carrying capacity is treated as if you were one size category smaller.


Anti-Feat: Sickly

Not only are you prone to getting sick, you are likely to stay sick much longer than most people. Bad weather affects you much more than most people and you really should try to stay as far away from poison as possible.
You have -1 to Constitution.
You have disadvantage on Constitution saving throws.
You have 1 less hp per level.


Anti-Feat: Slow

Maybe you have an injury, maybe you don't have as much stamina, or maybe you just don't move as fast as most people. Whatever the case, your companions always seem to be waiting for you to catch up.
You have -1 to Dexterity or Constitution.
Your movement speed decreases by 10 ft.


Anti-Feat: Socially Awkward

It's hard to explain, but to put it simply you just don't get others. It's often frustrating for both you and them, and you tend to have to work twice as hard and twice as long to get what seems to just come naturally to others.
You have -1 to Charisma.
You have disadvantage on all Charisma checks and saving throws.
You also have disadvantage on contested ability checks against another character's Charisma check.


Anti-Feat: Sucker

You're the one they talk about being born every minute. You've fallen for every con, bluff, deception, and spurious sales pitch under the sun… and a few that have never seen daylight.
You have -1 to Intelligence or Wisdom.
You have disadvantage on all contested ability checks against Charisma (Deception), Charisma (Persuasion), and Dexterity (Sleight of Hand) checks.
If someone attempts to sell you something questionable or that you just don't need, you must make either a Wisdom saving versus their passive Deception or an Intelligence saving throw versus their passive Persuasion as appropriate to not buy it.
If you ever go shopping alone, you will always pay at least 50% more for any purchase you make than you otherwise would have.


Anti-Feat: Uncoordinated

You just seem to have problems getting your limbs to move with each other. You frequently fumble items and stumble along in the street when anything distracts you.
You have disadvantage on any Action or Ability check that requires the use of both hands.
You have disadvantage on any Action or Ability check made while walking, swimming, climbing, or otherwise moving under your own power.
You have disadvantage on Wisdom (Perception) checks when performing any complicated task.


Anti-Feat: Unlucky

If something bad is going to happen, it's likely going to happen to you.
You may neither possess a beneficial dice re-rolling feature nor benefit from another's.
The first time you roll a natural 20 after each Short or Long Rest, you must re-roll the die and take the new roll.


Anti-Feat: Vulnerable

Choose an ability score where you have saving throw proficiency.
You have -1 to that ability score.
Your maximum score for that ability is reduced by 2 for as long as you possess this Anti-Feat.
You lose proficiency in saving throws involving that ability. You may never add any part of your proficiency modifier to those saving throws for whatever reason so long as you possess this Anti-Feat.
You do not qualify for any form of the Resilient Feat.


Anti-Feat: Walking Disaster

You are prone to mishap and disaster. You have at least twice as many accidents as anyone else you've ever met.
You may not possess Luck Points, Luck features from race or class, or any other beneficial dice-rerolling ability. You may, however, benefit from an ally's.
You automatically (or critically) fail any roll on a d20 if you roll a natural 1 or a natural 2.
You do not qualify for any Feat that would increase your critical success range.

[JNAProductions]

Absent-Minded is a no-brainer for any non-caster.

Anosmia is also a no-brainer for dwarves. Normal saves on poison for an extra feat?

Bad-Arm is no-brainer for Wizards or other main casters.

Blind is too bad-why can't you even attempt ranged attacks?

Bum Leg is, shockingly, a no-brainer for Monks. A 5' penalty is nothing compared to their bonuses.

Deaf makes no sense. Why would you have disadvantage on stealth? Also, is way too good.

Disability is a no-brainer for anyone with a dump stat.

Foolish is fine.

Hemophiliac is fine.

Illiterate, while quite punishing in the fluff... Too good.

Inept is fine.

Klutz might be okay? But might not be.

Monolingual is too good.

Numb is too good, and also annoying. If I'm the DM, I don't WANT to track a player's HP. That's more work for me.

One Arm is too good for Wizards and other casters.

One Eye is too good for anyone but scouts.

One Leg might actually be okay. It halves your speed, and you can never Dash.

Pariah is overly punishing. You can NEVER succeed on half of all Charisma checks, anywhere? That makes no sense.

Phobia might be okay, but feels too good.

Scrawny is too good for anyone who doesn't care about Strength.

Sickly actually feels okay.

Slow is too good.

Socially Awkward is too good.

Sucker's too good.

Uncoordinated might be okay.

Unlucky is far too broad. As written, you can never gain advantage. Ever.

Vulnerable is too good.

Walking Disaster is too good. Just pick a race without luck features (everyone but Halfling) and don't be in a situation where 2s would work, which is basically everytime ever.

[enderlord99]

So... flaws?

[Crisis21]

Absent-Minded is a no-brainer for any non-caster.

True, but it is meant to really hurt exploration attempts as Intelligence is a big exploration and investigation stat.
It's because Intelligence saves are almost never used in RAW, isn't it?

Anosmia is also a no-brainer for dwarves. Normal saves on poison for an extra feat?

Yeah, but it kind of defeats one of the main purposes of playing a dwarf, which is the bonus against poison.

Bad-Arm is no-brainer for Wizards or other main casters.

How would you improve it in that respect?

Blind is too bad-why can't you even attempt ranged attacks?

Because you can't see what you're trying to hit? Also, Blind should be pretty bad given how important sight is.

Bum Leg is, shockingly, a no-brainer for Monks. A 5' penalty is nothing compared to their bonuses.

You're right. I may add a prerequisite that you can't have any levels in Monk for this one.

Deaf makes no sense. Why would you have disadvantage on stealth? Also, is way too good.

You have disadvantage on Stealth because you can't tell how much noise you're making. Also, how might I improve it?

Disability is a no-brainer for anyone with a dump stat.

Well, yeah. This is the basic 'I trade two points from my dump stat for a free Feat' one. Only with the caveat that you can't make up for it with powerful magic items later.

Foolish is fine.

Yeah, because Wisdom saves are everywhere.

Hemophiliac is fine.

Hemophiliac is a death sentence waiting to happen. Especially at low levels.

Illiterate, while quite punishing in the fluff... Too good.

If one member of the party has it, maybe, but a good DM will find ways to exploit this mercilessly.

Inept is fine.

Cool.

Klutz might be okay? But might not be.

Klutz is Foolish for Dexterity.

Monolingual is too good.

Only if your DM doesn't pay attention to what language is being spoken.

Numb is too good, and also annoying. If I'm the DM, I don't WANT to track a player's HP. That's more work for me.

Yeah... this one sounded cool in my head, but it has too many moving parts to it. I may just scrap it.

One Arm is too good for Wizards and other casters.

Same issue there for Bad Arm, really. How might I improve it? Aside from doing something ridiculous like making somatic components difficult.

One Eye is too good for anyone but scouts.

I dunno. Most spells that require attack rolls are ranged.

One Leg might actually be okay. It halves your speed, and you can never Dash.

Yeah, I kind of like this one.

Pariah is overly punishing. You can NEVER succeed on half of all Charisma checks, anywhere? That makes no sense.

You ever seen how people treat pariahs? It's a really raw deal. And it's not 'anywhere', just where people know you and your reputation. If you can get out of the city/country/wherever, it effectively becomes a non-issue. Might scrap just because of that though.

Phobia might be okay, but feels too good.

Phobia is freaking debilitating. Fear is one of the more detrimental conditions in the game, is part of why Wisdom saves are so important, and why features like the Paladin's iconic immunity to magical fear even exist. And with this, all those features that negate or give advantage versus Fear mean squat the moment your phobia comes up. And any DM worth their salt will make sure it comes up at the worst possible times.
The only saving grace is that phobias only come up sometimes.

Scrawny is too good for anyone who doesn't care about Strength.

Much like Absent Minded is too good for anyone who doesn't care about Intelligence?

Sickly actually feels okay.

Like Hemophiliac, Sickly is one of those things that probably make people ask why the heck your character is adventuring in the first place.

Slow is too good.

Yeah, I'm not particularly wild about it myself actually.

Socially Awkward is too good.

How? Do you play characters that don't give a crap about Charisma and social interaction?

Sucker's too good.

Sucker's a great way to end up with a perpetually empty wallet.

Uncoordinated might be okay.

Cool.

Unlucky is far too broad. As written, you can never gain advantage. Ever.

How so? Advantage is 'roll two dice, take the higher one'. No re-rolling involved. Though I may need to buff it because it's supposed to be the counter to the Lucky Feat.

Vulnerable is too good.

It's a direct inversion of the Resilient Feat, plus you're giving up one of your two precious starting saving throw proficiencies in addition to a reduced maximum in the stat, so I feel it's balanced.

Walking Disaster is too good. Just pick a race without luck features (everyone but Halfling) and don't be in a situation where 2s would work, which is basically everytime ever.

Honestly, if you're not playing with critical failure effects on nat 1s, then this really doesn't mean much. I'm thinking I should fold this into Unlucky at the very least. Maybe buff the effect to include nat 3s as well...

So... flaws?

Pretty much, but I'm not calling them that to avoid confusion regarding roleplaying character flaws people usually take with their background. I'm not the only one doing that for 5e.

[Crisis21]

Revamped Numb. Still has a lot of moving parts, but it no longer requires the DM to do more work.

Anti-Feat: Numb

For some strange reason, you do not have a sense of touch. This extends to your sense of taste. You cannot feel pain at all, and often suffer more injury than you think and even injure yourself without realizing it.
You automatically fail any Action or ability check requiring a sense of touch or a sense of taste.
You have disadvantage on all Wisdom (Perception) and Intelligence (Investigation) checks involving physical contact.
You have disadvantage on all Tool checks.
You have disadvantage on saving throws versus Exhaustion and Death saving throws.
You are immune to pain.
You have advantage on concentration checks while above half health.
If a saving throw would let you avoid damage, you still take half the damage you would avoid (¾ damage if normally ½ and ½ damage if normally null (¼ if you are a Rogue using Evasion).
When you are below half health, you take 1d10 worth of damage any time you take an action, bonus action, or reaction.
If you undertake strenuous action, such as exceeding your normal carrying capacity or lifting heavy objects, you must make a DC 15 Strength saving throw or take 1d10 damage from overstressing your body.

[Crisis21]

Figured out the problem with Vulnerable. I forgot to include that it makes you ineligible for the Resilient Feat, meaning you can't trade your lesser saving throw (like Charisma) for a greater one (like Dexterity). I have fixed this.

[Quellian-dyrae]

What if you did something like saying anti-feats could be "major" or "minor". Some, like Hemophiliac or Sickly, might always be major. Others would default to minor and have certain requirements for being considered major, basically being a sort of character where the anti-feat will have a serious impact. For example, Absent-Minded would be considered a major anti-feat for characters who have class features fueled by Intelligence or spellcasting abilities.

Minor anti-feats would give something other than a full bonus feat. Maybe an ability score increase (which can't go to your highest score) or a skill proficiency or some such. Major anti-feats give you a full bonus feat.

Alternately, a good rule of thumb for balancing negative effects in general is that the GM should control when they come up, not the player. Maybe give them things like X times per Y, the GM can do Z. Maybe adjust the frequency based on how much impact the passive effects of the flaw would have. So you might say something like:

Anti-Feat: Absent-Minded

Let's face it, you really would forget your head if it wasn't attached.
You have -1 to Intelligence.
You have disadvantage on Intelligence checks, saving throws, and concentration checks.
Twice per long rest, the GM can negate an action you take as you lose focus and become briefly distracted. You retain all resources that would be spent, you just lose the action with no effect. If you have proficiency in any Intelligence skills or class features that use Intelligence, the GM can do this one fewer time per long rest. If you have spellcasting ability, the GM can do this one fewer time per long rest.

Anti-Feat: Bad Arm

One of your arms doesn't work quite right. You might have been born that way or you might have had a broken arm earlier in life that never healed right. Your bad arm is not considered your dominant arm.
You have -1 to Dexterity or Strength.
You may not hold any weapon in that hand that doesn't possess the Light property.
You may not wield any two-handed weapon with the Heavy property.
Attack rolls made using that arm are done with disadvantage.
You have disadvantage on all Strength (Athletics) and Dexterity (Acrobatics) checks requiring use of your arm.
If you use a shield on your bad arm, it only grants +1 AC instead of +2.
Your dead lift capacity is reduced to your maximum encumbrance.
Twice per long rest, the GM can impose Disadvantage on a physical check you make (that is, a check based on Strength, Dexterity, or Constitution), or grant Advantage on a physical check an opponent makes against you,
as the physical effort jostles your bad arm painfully. If you have proficiency in any skills that use the same ability score as you took the penalty on or class features fueled by that score, the GM can do this one fewer time per long rest. If you have class features that involve weapon attacks, the GM can do this one fewer time per long rest.

This also gives the GM prerogative to "balance" the impact of the anti-feat with the feat chosen. Take a feat that is more fluffy and suited to your character concept without granting significant mechanical advantage? Maybe the GM doesn't always invoke the penalty the maximum times it can, or does so in more minor situations. Take a feat that synergizes heavily with your build? Expect to get your most important actions delayed, or disadvantage applied to important saves, or whatever.

[clash]

It has always been in my mind to pair specific anti-feats with specific feats to get around this abuse. So the anti-feat will carry a direct cost for the character taking it.

For example pairing bad arm with defensive duelist. You get the perks, but it comes with a direct and thematically linked cost.

[petermcleod117]

So, would taking an anti-feat grant you a normal feat as well, just as with the Flaw system?

[Crisis21]

What if you did something like saying anti-feats could be "major" or "minor". Some, like Hemophiliac or Sickly, might always be major. Others would default to minor and have certain requirements for being considered major, basically being a sort of character where the anti-feat will have a serious impact. For example, Absent-Minded would be considered a major anti-feat for characters who have class features fueled by Intelligence or spellcasting abilities.

Minor anti-feats would give something other than a full bonus feat. Maybe an ability score increase (which can't go to your highest score) or a skill proficiency or some such. Major anti-feats give you a full bonus feat.

Alternately, a good rule of thumb for balancing negative effects in general is that the GM should control when they come up, not the player. Maybe give them things like X times per Y, the GM can do Z. Maybe adjust the frequency based on how much impact the passive effects of the flaw would have. So you might say something like:

Anti-Feat: Absent-Minded

Let's face it, you really would forget your head if it wasn't attached.
You have -1 to Intelligence.
You have disadvantage on Intelligence checks, saving throws, and concentration checks.
Twice per long rest, the GM can negate an action you take as you lose focus and become briefly distracted. You retain all resources that would be spent, you just lose the action with no effect. If you have proficiency in any Intelligence skills or class features that use Intelligence, the GM can do this one fewer time per long rest. If you have spellcasting ability, the GM can do this one fewer time per long rest.

Anti-Feat: Bad Arm

One of your arms doesn't work quite right. You might have been born that way or you might have had a broken arm earlier in life that never healed right. Your bad arm is not considered your dominant arm.
You have -1 to Dexterity or Strength.
You may not hold any weapon in that hand that doesn't possess the Light property.
You may not wield any two-handed weapon with the Heavy property.
Attack rolls made using that arm are done with disadvantage.
You have disadvantage on all Strength (Athletics) and Dexterity (Acrobatics) checks requiring use of your arm.
If you use a shield on your bad arm, it only grants +1 AC instead of +2.
Your dead lift capacity is reduced to your maximum encumbrance.
Twice per long rest, the GM can impose Disadvantage on a physical check you make (that is, a check based on Strength, Dexterity, or Constitution), or grant Advantage on a physical check an opponent makes against you,
as the physical effort jostles your bad arm painfully. If you have proficiency in any skills that use the same ability score as you took the penalty on or class features fueled by that score, the GM can do this one fewer time per long rest. If you have class features that involve weapon attacks, the GM can do this one fewer time per long rest.

This also gives the GM prerogative to "balance" the impact of the anti-feat with the feat chosen. Take a feat that is more fluffy and suited to your character concept without granting significant mechanical advantage? Maybe the GM doesn't always invoke the penalty the maximum times it can, or does so in more minor situations. Take a feat that synergizes heavily with your build? Expect to get your most important actions delayed, or disadvantage applied to important saves, or whatever.

Hmm... I'll take that under advisement. Especially with those two.

Actually, for the first one I might add something like this:

Whenever you undertake a task that takes longer than ten minutes, you must make a DC 15 concentration check using your Intelligence modifier or become distracted from your task. If the task involves watching a person or place, then you have disadvantage on all d20 rolls made towards that objective. If it involves research or crafting something then the task takes one hour longer for every point you failed the check by as you become sidetracked and completely lose track of time (you may be reminded of an appointment by another character in this situation, but this will cause your task to remain incomplete).

It has always been in my mind to pair specific anti-feats with specific feats to get around this abuse. So the anti-feat will carry a direct cost for the character taking it.

For example pairing bad arm with defensive duelist. You get the perks, but it comes with a direct and thematically linked cost.

Eh... unless there's one that screams out for a pairing (like Blind and Blindsense), then I dislike this.

The main thing I'm counting on to keep this from being overly abused is the DM setting a hard limit over how many Anti-Feats a player can take in exchange for a bonus Feat at character creation. I'm thinking one.

So, would taking an anti-feat grant you a normal feat as well, just as with the Flaw system?

Pretty much.



Re-did Numb again...

Anti-Feat: Numb

For some strange reason, you do not have a sense of touch. This extends to your sense of taste. You cannot feel pain at all, and often suffer more injury than you think and even injure yourself without realizing it.
You automatically fail any Action or ability check requiring a sense of touch or a sense of taste.
You have disadvantage on all Wisdom (Perception) and Intelligence (Investigation) checks involving physical contact.
You have disadvantage on all Tool checks.
You have disadvantage on saving throws versus Exhaustion and Death saving throws.
You are immune to pain. You cannot be directly tortured or take damage from illusions.
You have advantage on concentration checks while above half health.
If you are attacked and damaged by a creature hidden from you, you are not made aware of their location or even their existence unless someone else is able to point them out to you. If this happens during the surprise round, then your attacker retains surprise. In any case, the DM is under no obligation to tell you you have taken damage or how much until you notice your wounds (DC 15 Perception check), are made aware of them by another, or the DM thinks you might have been killed by the damage.
If a saving throw would let you avoid damage, you still take half the damage you would avoid (¾ damage if normally ½ and ½ damage if normally null (¼ if you are a Rogue using Evasion).
When you are below half health, you take 1d10 worth of damage any time you take an action, bonus action, or reaction.
If you undertake strenuous action, such as exceeding your normal carrying capacity or lifting heavy objects, you must make a DC 15 Strength saving throw or take 1d10 damage from overstressing your body. This includes any attempt to escape being grappled.


Edit: Tweaked Deaf as well and added Mute.

Anti-Feat: Deaf

You are completely deaf.
You automatically fail any Action or ability check requiring hearing.
As you cannot tell how much noise you are making, you have disadvantage on Dexterity (Stealth) checks.
If an enemy you cannot see attacks you, it is considered a surprise attack.
Unless you possess the Observant Feat or some other feature allowing you to read lips, you cannot understand spoken language at all.
Note: You do not automatically know any form of Sign Language unless you gained it through a bonus Language from your background or another source.


Anti-Feat: Mute

You cannot speak at all and must communicate with gestures or written language.
You may not attempt any form of Charisma (Persuasion) or Charisma (Deception) check unless you can somehow make yourself understood to the other person.
You have disadvantage on any Charisma check where speaking would significantly improve your chances of success.
You may not cast any spell with a verbal component.
Note: You do not automatically know any form of Sign Language unless you gained it through a bonus Language from your background or another source.


Edit2: Addition to Bad Arm

Whenever you cast a spell with a somatic component, roll a d4. On a 1, you flub the somatic component and the spell fails.