Traits, inspired/adapted from the Fallout games, are optional choices made at character creation to help customise characters slightly. The changes should be mechanically neutral, or potentially slight improvements depending on how your character is played, but they should allow a small degree of extra customisability.
Characters as standard can select a maximum of two traits, though they do not need to choose any if they don't wish to.
Blaze of Glory - You feel of a rush of adrenaline whenever you're nearing death, pushing beyond normal limits. For one minute after dropping to 50% health, the ability modifier for your attack and damage rolls are doubled. However, you are also vulnerable to damage from all weapon attacks for the duration. This can occur once per long rest.
Bloody Mess - For some reason, deaths around you just seem a little...messier. When you reduce a creature to 0 HP with an attack, the creature explodes violently in a bloody mess. This explosion deals no extra damage, however it is very gory and ruins the body.
Bruiser - You're big, slow, and hit hard. That's all you really need. Your strength score increases by 1, your dexterity score decreases by 2, and your movement speed is reduced by 5 feet.
Built to Destroy - Weapons seem to do a bit more for you than others, but they also break far faster. Attacks made with weapons now critically strike on a roll of 19 or 20. However, when you roll a 1 your weapon deals the damage and then is itself damaged and deals 1 damage and have disadvantage on attack rolls. Magic weapons can be restored as part of a long rest by expending 2 hit dice. Non-magical weapons are damaged beyond repair.
Bullied - You were bullied as a child, and sometimes it just makes you lash out. Whenever you use your reaction to make an attack, you deal an extra 1 damage when you hit. You have a permanent -2 on Intimidation rolls.
Claustrophobic - You really don't like being inside. While inside a room that isn't at least 20' by 20' you have disadvantage on any saving throws against being Frightened. While in a larger space than 20' x 20', you have advantage on saving throws against being Frightened.
Early Bird - They get the worm. You gain a +2 to skill checks using the Athletics, Acrobatics and Insight skills during the hours of 6:01pm to 6:00AM, and a -1 to those same checks between the hours of 6:01AM and 6:00PM. This is mutually exclusive with Night Person.
Edge of Death - You teeter a bit closer to death than most. When you make death saving throws you now require only two successes to stabilise, but also suffering two failures kills you.
Fast Metabolism - Scratches and bruises never seemed to bother you. But a drop of alcohol? That's a whole different story. Whenever you are healed, either magically or otherwise, the amount you are healed is increased by 1.5x as much. However you have a permanent vulnerability to poison damage and disadvantage on saves against being poisoned.
Fast Aim - You love firing your bow, sometimes a bit too much. Once per turn when you make an attack with a ranged weapon, roll a d10. On a roll of 9-10 you can make one extra attack with your ranged weapon this turn. However, your first attack with a ranged weapon each turn and the potential extra attack both suffer a -3 on their attack rolls.
Finesse - You've always given more weight to an attack made in the right place than an attack made with the right force behind it. Attacks made with weapons now critically strike on a roll of 19 or 20. However you no longer apply your ability modifier to damage for weapon attacks.
Four Eyes - Bad natural eyesight won't hold you back. When wearing glasses, you have advantage on perception checks using sight. When not wearing glasses, you have disadvantage on perception checks using sight.
Gifted - You were always a bit special, but that also made you a bit of a slacker. At the end of a long rest roll a 1d6. Until your next long rest you gain +2 to the ability that the d6 refers to (Strength=1, Dexterity=2, etc.) However, you lose proficiency with one skill.
Glutton - Your love of food keeps you from being fast on your feet, but when you eat so much, you're going to get used to bad food too. Your movement speed is reduced by 5', and you have advantage on saves against being poisoned.
Good Natured - Sometimes it'd be nice if everyone just got along. You gain a permanent +3 to rolls made for the Persuasion, Medicine, Investigation, Animal Handling and Nature skills. You also gain a permanent -1 to all attack rolls, be they for weapon or spells.
Heavy Handed - Consistency is key, and sometimes you have to sacrifice a bit of finesse for that. You gain a permanent +1 damage to attacks made with melee weapons or unarmed strikes. Whenever you critically strike with melee weapons or unarmed strikes, the damage from the critical dice is halved.
Hoarder - Yes, you need to be carrying fourteen different bars of soap. You never know when you're going to need them! Your carrying capacity increases by 25lbs, but you have disadvantage on initiative rolls whenever you have more than 10lbs of carrying capacity not in use.
Hot Blooded - Reckless might get some people killed, but the best defense is a good offense. You have a permanent -3 to your armour class, however once per short rest you can choose to take an extra action on your turn. If you take the attack action with this extra action, you can make one attack with it only.
Illiterate - Why bother learning to read when other people can do it for you? You lose the ability to read and write, however you gain proficiency in Strength, Intelligence or Charisma saving throws.
Jinxed - Bad luck has followed you your whole life, and sometimes it rubs off on other people. Whenever a creature makes an attack roll against you, they automatically miss on a roll of 1, 7, 13, and 17, as if they had rolled a 1. Whenever you make an attack roll against a creature, you automatically miss on a roll of 1, 7, 13, and 17, as if you had rolled a 1.
Loose Cannon - Your throwing arm is your pride and joy, but speed is more important than distance. When you take the attack action and throw a weapon, roll a 1d6. On a 6 you can throw one extra weapon (assuming you have one on hand) this turn. However, the range of all throwing weapons, both normal and long, is halved for you.
Night Person - Sleeping in is really the way to go. You're most productive during the Witching Hour anyway. You gain a +2 to skill checks involving Intelligence and the Perception skill during the hours of 6:01pm to 6:00AM, and a -1 to those same checks between the hours of 6:01AM and 6:00PM. This is mutually exclusive with Early Bird.
One-Hander - Maybe your offhand is just a bit weak, but you like to say you're focusing your efforts where it's most important. When you are wielding a single one handed weapon and no shield, you have +2 to weapon attack rolls. When you are wielding a two handed weapon, you have -4 to weapon attack rolls.
Paranoid - It's not paranoia if they're really out to get you...or is it? You gain a +2 bonus to your Perception skill, but suffer a -2 to all Initiative rolls.
Romantic Appeal - Whatever the right "stuff" is, you've got it. But that can put people off. You have advantage on any charisma skill checks made against creatures that are attracted to you, however you have disadvantage on the same checks against creatures which are not.
School Specialist - Some spellcasters say "adaptability is key". I say "I cast Fireball". You pick one school of magic. All spells you cast from this school are treated as being upcast one spell level. Spells from all other schools are treated as if they're one spell level higher. For example, if you chose Necromancy as your school, Burning Hands would be require a 2nd level spell slot, but still only cast as if at first level.
Skilled - While some people are naturally gifted, you've always been more of just a hard worker. You gain proficiency and expertise in two skills of your choice, however because of your skill focus, you can no longer raise ability scores above 18 without magical aid.
Small Frame - You were never the biggest around, but you make up for it in speed. You gain +1 to your Dexterity score, but your carrying capacity is halved and you have disadvantage on athletics checks.
Truth Teller - You cannot tell a lie, perhaps due to magic, perhaps due to your upbringing. You roll Persuasion checks with advantage because of your air of honesty, but all Deception rolls are treated as rolling a 1 and forcing yourself to tell a lie often has violent physical reactions such as vomiting or hysterical crying. Stretching the truth can likewise cause problems.
Wild World - Lets. Get. Wild. Taking this trait makes the world just a little bit stranger, a little bit less serious, and a little bit wilder. The chance of strange occurrences should increase the more party members take this trait.