RPGBOT - DnD 5e - The Barbarian Handbook

DnD 5e - The Barbarian Handbook

Last Updated: March 13th, 2019

Disclaimer

I will use the color coding scheme which has become common among Pathfinder build handbooks, which is simple to understand and easy to read at a glance.

Red: Bad, useless options, or options which are extremely situational.
Orange: OK options, or useful options that only apply in rare circumstances
Green: Good options.
Blue: Fantastic options, often essential to the function of your character.

I will not include 3rd-party content, including content from DMs Guild, even if it is my own, because I can't assume that your game will allow 3rd-party content or homebrew. I also won't cover Unearthed Arcana content because it's not finalized, and I can't guarantee that it will be available to you in your games.

Temporary Note: I am currently waiting to include content from the Wayfarer's Guide to Eberron. According to Dragontalk (the official D&D podcast), it's in a semi-finished state and is still subject to change, which could mean that character options in the book will see major changes before final publication. Once the book is complete, physical copies will be released and I will update to address the new content.

Introduction

Barbarians are all about getting angry and dealing damage. They have a ton of hit points, resistance to damage, and Rage gives a wonderful bonus to damage. Barbarians don't get much in the way of skills, so generally they're stuck as combat monsters, but they function equally well as a Defender and a Striker.

Barbarian Class Features

Hit Points: d12 is the biggest hit die available.

Saves: Strength saves are fairly rare, but Constitution saves are common and typically very problematic.

Proficiencies: Medium armor and martial weapons will get you a long way, but you get no tool proficiencies, and only two skills.

Rage: Rage is the Barbarian's defining class feature. The bonus damage isn't huge, but it's reliable and consistent. The resistance to damage makes Barbarians exceptionally durable. You can rage multiple times in the same encounter if you absolutely need to, but your number of rages per day is limited, so try not to do so if you can avoid it.

Unarmored Defense: This is great flavor for the Barbarian, but won't do much good for you unless your abilities are very high. Your Dexterity and Constitution modifiers need to total +7 to match the total AC bonus provided by half plate armor. That's generally achievable by level 8 unless you rolled for ability scores, and assuming that you started with 14 Dexterity and largely ignored Strength. More realistically, you should expect to hit 20 Constitution by 12th level, and even then Unarmored Defense will only break even with Half plate. If magic armor is an option you'll need to put an ability increase into Dexterity before you have a good reason to drop your armor.

Reckless Attack: Rage makes you resistant to damage from normal weapons (Magical weapons which do weird damage types still work fine), so advantage on attacks against you doesn't matter as much. Go crazy. Kill all of the things.

Danger Sense: In medium armor your dexterity probably isn't fantastic, but advantage on any save is fantastic.

Primal Path: See "Subclasses - Primal Paths", below.

Extra Attack: Two attacks means potentially twice as much damage in a turn, and twice as much opportunity to apply your rage bonus to damage.

Fast Movement: Amusing, but not game-changing.

Feral Instinct: You are basically immune to surprise attacks. Advantage on initiative will allow you to go first frequently, so be sure to get into position to keep enemies from reaching your squishy allies.

Brutal Critical: Critical hits are very rare, and this makes it difficult to use a Maul effectively.

Relentless Rage: This will keep you conscious for a long time if you get hit with a low numbers of high-damage attacks, but lots of small attacks will raise the DC too quickly for this to remain effective. Be sure to eliminate weak but numerous enemies before your HP starts getting scary.

Indomitable Might: By now you might very easily have 20 Strength, so you're guaranteed to get a ridiculously high roll on any Strength check. Remember that saves and attacks aren't checks, so you still need to roll high on those.

Primal Champion: The equivalent of 4 ability increases all at once. Your abilities should be absurd by this point, so now may be a good time to abandon your armor in face of running around slaying monsters in your undergarments.

Subclasses - Primal Paths

Ancestral Guardian^XGtE: This archetype diminishes the Barbarian's role as a Striker, and dramatically improves its role as a Defender. If you have squishy melee allies like monks or rogues in the party, they'll benefit greatly from this archetype. The only drawback is that the archetype provides no abilities which increase your damage output, which makes it important to have another Striker in the party to compensate. It also notably doesn't have an ability to consume your Bonus Action, which makes this archetype a good choice for two-weapon fighting.
- Ancestral Protectors: This is an amazing aggro mechanic. Sure, the target can attack other people, but they do so with Disadvantage and do half damage. At that point, attacking anyone except you seems pointless.
- Spirit Shield: There is no limitation on how often you can use this except that it uses your Reaction. This is a massive increase to your party's survivability, and even if this never scaled it would still be fantastic.
- Consult the Spirits: Augury and Clairvoyance are two of my favorite divinations because they're simple, but extremely useful. Use Augury any time you make a major decision with unknown risks. Use Clairvoyance to scout around corners, behind doors, etc. By this level actual spellcasters will be able to do this with ease, but you can use this ability once per short rest without spending spell slots.
- Vengeful Ancestors: As a reaction, reflect up to 4d6 damage directed at an ally back to the attacker. Amazing. You might encourage your allies to draw fire just so you can use this.
Battlerager^SCAG: The Battlerager's abilities center around the use of Spiked Armor. If you can't get spiked armor for whatever reason, your Primal Path suddenly becomes worthless. If you want to use that shiny magic armor you found, you're similarly out of luck. The class abilities give you some nice damage options, and Battlerager Charge is great, but the abilities aren't as useful or as exciting as Berserker. The racial restriction is also frustrating, but the dependency on Constitution means that a Dwarf would be a good choice anyway.
- Battlerager Armor: A free attack as a bonus action is great. Don't forget that your rage bonus to damage still applies. The ability to deal damage when you grapple is also nice if you like to grapple.
- Reckless Abandon: This won't be a big pile of hit points, and considering you've already got d12 hit points and good Constitution, this is fairly unimportant.
- Battlerager Charge: Similar to the Charger feat, but you can use multiple attacks as an Action.
- Spiked Retribution: Not a lot of damage at this level, but by now many enemies will have multiple attacks.
Berserker^PHB: The Berserker is a the classic Barbarian. If you want to get mad and wreck people's faces, the Berserker is a good choice. The important abilities give you the ability to get extra attacks, capitalizing on the flat damage bonus from Rage and on the huge damage die from your two-handed weapon. Fun fact: "Berserker" translates to "Bear Warrior", but the Berserker has nothing to do with bears.
- Frenzy: When you absolutely, positively have to kill every living thing in a room. An extra attack as a bonus action gives you the action economy of two-weapon fighting with the possible damage die of a single two-handed weapon. Exhaustion can really mess you up, so use this sparingly, and be sure to check what penalties you get for each level of exhaustion (PHB pg. 291).
- Mindless Rage: This makes you immune to two ways to take you out of combat without wearing down your huge pile of hit points.
- Intimidating Presence: The effect only lasts until the end of your next turn unless you spend your action to extend it. Fortunately extending the duration doesn't allow the creature to make additional saves so you can use this to keep enemies frightened while your allies kill them at range.
- Retaliation: More attacks are always fantastic, so get into melee and try to draw fire. Remember that this only works on enemies within 5 feet, so don't bother trying to use a polearm.
Storm Herald^XGtE: A great choice for barbarians with unknown or fluctuating party compositions, the ability to change your Environment means that you can adapt your abilities to suit the needs of your party. However, you can only make this change once per level, and if your choice of Environment is problematic in an encounter you may be unable to make use of your subclass abilities. Storm Herald is heaviloy dependant on your Bonus Action, so avoid two-weapon fighting.
- Environment Choices: Your choice of environment defines the benefits of the subclass. You can only change your environment once every time you gain a level, so expect to be locked into your choice for several game sessions. Generally you'll be happy with your choice for a long time, but you might consider changing if your party composition changes, or if you get a new subclass ability that makes another option more appealing.
  - Desert: Excellent for raw damage and for handling crowds of enemies.
  - Sea: Functions best in aquatic campaigns. Land-locked campaigns will lose many of the benefits.
  - Tundra: The best defensive option. Excellent if your party already does plenty of damage.
- Storm Aura: Damage enemies or grant temporary hit points to yourself and your allies. Only functions while raging, but it makes your rage super cool.
  - Desert: If you don't have other melee allies, or if your party has trouble handling crowds of enemies, this is a good option. However, the damage is small and still consumes your bonus action, so you may do more damage using your bonus action for two-weapon fighting.
  - Sea: Single-target damage, and the average damage isn't much better than the damage from Desert. If you have another melee ally but still want damage, this is fine.
  - Tundra: This can affect you and any number of allies in the 10-foot aura. Start every encounter within 10 feet of your allies and you'll always have temporary hit points. The ability to renew them as a bonus action means that you can consistently pad your own hit points while you're up front taking damage. On rounds where you've still got temporary hit points, consider using your bonus action for two-weapon fighting or something.
- Storm Soul:
  - Desert: Fire damage is one of the most common damage types.
  - Sea: Lightning damage isn't especially common. This will generally only be useful in aquatic campaigns.
  - Tundra: Cold damage isn't as common as fire, and the weak version of Shape Water isn't especially useful.
- Shielding Storm: This requires your allies to stay within your aura, which in some cases might put them in the way of effects they're trying to resist, like breath weapons or fireballs. Still, it's an occasionally useful option.
- Raging Storm:
  - Desert: A little bit of free damage on your Reaction.
  - Sea: Not your Bonus Action, but your Reaction. You won't be able to make opportunity attacks for the round, but the rest of your attacks will be at Advantage against the prone target, and you can still use your Bonus Action for the active effect of Storm Aura.
  - Tundra: Keep an enemy from running away. If you use Shove to knock them prone, they can't get back up because they don't have enough speed.
Totem Warrior^PHB: Totem Warrior is more customizable than Berserker, but it's also more complex to play. For a Defender, I recommend focusing on Bear. For a Striker, I recommend focusing on Eagle. For a supporty type thing, Start with Wolf then pick up Bear for Totemic Attunement.
- Spirit Seeker: Very situational.
- Totem Spirit: Totem Spirit defines your combat tactics. Bear is for Defenders, Eagle is for Strikers, and Wolf is for Barbarians with other Strikers in the party.
  - Bear: You are basically an unstoppable pile of damage resistance and hit points.
  - Eagle: Running around between enemies isn't something the Barbarian does on a regular basis, especially if you're the party's only Defender.
  - Elk^SCAG: Barbarians already get Fast Movement, so your speed should be fine.
  - Tiger^SCAG: Jumping almost never matters in a game where you can gain magical flight. This is especially frustrating because it only applies when you're raging.
  - Wolf: This is extremely helpful for Rogues in your party. Rogues get Sneak Attack for attacking enemies threatened by an ally, but giving them advantage makes them considerably more reliable. Unfortunately it doesn't do anything helpful for you.
- Aspect of the Beast: Remember that you don't need to select the same animal which you selected for Totem Spirit. The PHB options are mostly for flavor, but the options introduced in the Sword Coast Adventurer's Guide are considerably better.
  - Bear: Carrying capacity is usually ignored, and you can always buy a mule to carry your heavy stuff. The advantage on Strength checks only affects objects, and breaking objects isn't a frequent activity in most campaigns.
  - Eagle: Situational. The biggest advantage is seeing unimpeded in dim light, but if that is a problem you should get Darkvision.
  - Elk^SCAG: Overland travel generally happens in plot time, so in most campaigns this will have no percievable effect.
  - Tiger^SCAG: If you needed any of these skills, you should have gotten them from your background or your free class skills. If you need more skills, pick up the Skilled feat.
  - Wolf: Very situational.
- Spirit Walker: Commune With Nature isn't very powerful as far as divinations go, but it can be very useful when exploring new terrain.
- Totemic Attunement: Totemic attunement is an improvement to your combat tactics established by Totem Spirit.
  - Bear: Force nearby enemies to attack you instead of your allies. They can still move away from you, but that draws an opportunity attack from a huge horrifying Barbarian.
  - Eagle: Fly over enemies. Fly into the air to hit a flying wizard, then land on something until your next turn. This might even look like Wushu fighting if you do it right.
  - Elk^SCAG: This is a cool trip mechanic which allows you to knock an enemy prone without cutting into your attacks. You need to use it on large or smaller enemies, which covers most enemies, but at high level you'll frequently encounter very large foes which won't be affected by this ability.
  - Tiger^SCAG: Incompatible with the Charger feat, but a bonus action attack is always a good option and it doesn't require you to waste your Action on Dash so you canstill get your regular attacks.
  - Wolf: Knocking an enemy prone gives you advantage on attacks against them, including your second attack with the Extra Attack feature. Allies threatening that enemy can already get advantage from your if you selected Wolf for your Totem Spirit, so this may not be very useful.
Zealot^XGtE: A great choice for players who tend to die a lot, the Zealot makes surviving and recovering from death considerably easier. However, because many of its abilities are tied up in keeping you alive, it doesn't have great offensive abilities.
- Divine Fury: A whole bunch of bonus damage, and nothing fancy. Consider two-weapon fighting so that you have additional opportunities to apply the bonus damage if you're having trouble hitting.
- Warrior of the Gods: Generally dying is something that you work very hard to avoid, but if anyone's going to die in combat it's a barbarian. Spells which raise the dead have expensive material components, and this allows you to bypass them. So long as you're friends with a sufficiently high-level cleric, you don't need to worry about an untimely death.
- Fanatical Focus: Excellent for save-or-suck effects.
- Zealous Presence: Once per day and doesn't affect you. It gets more useful the larger your party is, so encourage your allies to summon creatures, use pets, etc.
- Rage beyond Death: Drink a potion of healing right before your rage ends and you're functionally unable to die due to hit points loss while raging.

Abilities

Barbarians are all about their physical ability scores. If your scores are good enough you can forgo armor, so it's nice to have adequate Dexterity and Constitution to beat the AC bonus provided by half plate.

Str: Barbarians are all about lots of Strength and big weapons, so Strength should almost always be your best ability.

Dex: 14 Dexterity is great to boost your AC with half plate. If you prefer to go armor-less, look for an item to boost your Dexterity so that you can spend your ability increases on Strength and Constitution.

Con: Second only to Strength. Barbarians take a lot of damage, so you need all the hit points you can get. Constituion also powers Unarmored Defense.

Int: Dump stat. Intelligence saves are very rare, and Barbarians don't get any Intelligence-based skills.

Wis: Wisdom saves are common, so don't dump it, but don't put a ton of effort into improving it.

Cha: Charisma only matters for a couple of the Barbarian's skills, and for the Berserker's Intimidating Presence. If you went for Totem Warrior and didn't pick up Intimidation, you can dump Charisma and use the points to boost your Wisdom.

Point Buy	Standard Array
Str: 15 Dex: 14 Con: 14 Int: 8 Wis: 10 Cha: 10	Str: 15 Dex: 13 Con: 14 Int: 8 Wis: 12 Cha: 10

Races

Look for bonuses to Strength and medium size so that you can effectively use big weapons like a Greataxe.

Aarakocra^EEPC: Flight is fantastic, but the Aarakocra's abilities don't work well for a Barbarian.

Aasimar^VGTM: Charisma won't do much for a barbarian.

Fallen: Tempting, but almost all of the useful stuff is from the subrace.
Protector: Access to flight is tempting, but you can get that from other places.
Scourge: Interesting, but you need a Strength bonus more than a Constitution bonus.

Bugbear^VGTM: Dexterity might not seem like an obvious benefit for a barbarian, and it's not as good as Constitution, but the AC bonus is still helpful. Reach makes it easy to compete with larger creatures or attack smaller foes at a distance, and Sneaky allows you to be an ambush predator.

Dwarf: Most of the Dwarf's racial traits are wasted on the Barbarian, but the Constitution bonus is great and Darkvision is always welcome. The Dwarven Fortitude racial feat can be a great way to keep yourself alive in combat if your AC is low and you don't have healing readily available.

Duergar^SCAG: In a subterranean campaign, this is at least on par with Mountain Dwarf. Otherwise, sunlight sensitivity is a huge problem.
Hill^PHB: A bonus to wisdom is nice, but not going to make a big difference. The bonus hit points is also helpful, but you already have a d12 hit die and a Constitution bonus from the general Dwarf traits.
Mountain^PHB: A bonus to Strength on top of the Dwarf's bonus to Constitution is perfect for a Barbarian.

Dragonborn^PHB: A bonus to Strength is great, but the bonus to Charisma is wasted unless you want to use Intimidating Rage a bunch. The Dragonborn's breath weapon is helpful for handling groups of weak enemies which a Barbarian would normally need to wade through one or two at a time.

Elf^PHB: A bonus to Dexterity isn't as helpful as one to Strength or Constitution, but the Elf's other racial traits are great for the Barbarian. Darkvision is excellent, and Keen Senses saves you a skill choice.

Drow: Nothing helpful for the Barbarian.
Eladrin^MToF: Fey Step is really good, but that's the only appeal.
High Elf: Nothing helpful for the Barbarian.
Sea Elf^MToF: +1 Constitution is the only thing you need from the Sea Elf.
Shadar-Kai^MToF: Dexterity and Constitution isn't ideal for a barbarian, but your AC will be really good, and you get a damage resistance and the ability to teleport.
Wood Elf: A wisdom bonus might help with your Wisdom saving throw, but that's about it.

Firbolg^VGTM: A bit too tricksy and indirect for a Barbarian.

Genasi^EEPC: Bonus Constitution isn't as good as Strength, but it boosts the Barbarians AC and hit points, both of which are important.

Air: Dexterity isn't particularly important for Barbarians, and the ability to hold your breath is extremely situational.
Earth: Bonus Strength, and the ability to move across difficult terrain unimpeded helps you to get into melee in situations where it's normally difficult to do so.
Fire: Intelligence is for Wizards. The resistance to fire is tempting, and Produce Flame is a decent option, but the spells don't really play to the Barbarian's strengths.
Water: Wisdom is a good defensive ability, and the spells are excellent utilities. Resistance to Acid is nice, but situational.

Gith: Githyanki are great, Githzerai are terrible and you should ignore them.

Githyanki^MToF: +2 Strength, some extra proficiencies, and Giyhtanki Psionics gives you some magic options to overcome problems that many barbarians can't handle.
Githzerai^MToF: Nothing helpful for Barbarians.

Gnome: Nothing helpful for the Barbarian.

Deep (Svirfneblin)^{EEPC / SCAG}: Dexterity and stealth abilities aren't useful for Barbarians.
Forest^PHB: Nothing helpful for the Barbarian.
Rock^PHB: The constitution bonus helps, but it's not nearly enough to make the Gnome viable for a Barbarian.

Goblin^VGTM: Nothing helpful for the Barbarian.

Goliath^VGTM/EEPC: Tailor-made to be a melee Monster. Bonuses to your important abilities, free Athletics proficiency, and Stone's Endurance adds a pile to your effective daily hit point total.

Half-Elf: Several of the half-elf variants are good choices, and if you want to excel at Intimidation half-elf is the way to go. Otherwise, the Mountain Dwarf and Variant Human will be better at killing things.

Aquatic^SCAG: Only if you're in an aquatic campaign.
Drow^SCAG: The spells are decent, and Faerie Fire presents a way to handle invisible foes which Barbarians normally can't handle, but you'll have trouble using Dancing Lights and Darkness.
High/Moon/Sun^SCAG: Weapon training is redundant, and Barbarians won't get much use out of a cantrip. You might consider green flame blade, but you'll have better damage output from relying on conventional attacks.
Keen Senses^SCAG: The sidebar describing half-elf variants specifices that you can take Keen Senses in place of Skill Versatility, or a trait based on your elf parentage. Keen Senses give you a single fixed skill, and you're giving up proficiency in any two skills. It should be immediately apparent that this is a terrible trade.
Wood^SCAG: Weapon training is redundant and Mask of the Wild won't be useful without Stealth proficiency, but Fleet of Foot is great if you want to be the world's fastest Barbarian
Vanilla^PHB: Two skills can get you quite a lot. Coupled with the Half-elf Charisma bonus you could easily be your party's Face.

Half-Orc^PHB: The Half-Orc is tailor-made for the Barbarian. Bonuses to Strength and Constitution are essential, Darkvision is great, and you save a skill choice on Intimidate. The Half-Orc's other abilities match some of the Barbarian's class features, but it appears that they work together, so you can essentially double-down on Brutal Critical and Relentless Rage. The Prodigy racial feat is excellent if you plan to use Athletics for grappling. The Orcish fury racial feat is tempting with a greataxe, but probably not worth the feat.

Halfling^PHB: A dexterity bonus is okay for Barbarians, but small size is a problem because you can't use big weapons like a Greataxe.

Ghostwise: Nothing helpful for the Barbarian.
Lightfoot: Nothing helpful for the Barbarian.
Stout: A small Constitution bonus, and resistance to poison. Like a small dwarf.

Hobgoblin^VGTM: The Consitution bonus and Saving Face are both great, but that's really the only thing that the barbarian can use.

Human^PHB: Versatile and fantastic at everything. The Prodigy racial feat is excellent if you plan to use Athletics for grappling.

Vanilla: Barbarians really only need two ability scores, but a +1 to all of your scores can be helpful if you use the point buy ability generation method to give yourself low, odd-numbered base abilities to save points.
Variant: You still get crucial bonuses to your Strength and Constitution, and you can get an awesome feat at level 1. Great Weapon Master seems like an obvious choice, but remember that at low level a -5 penalty to your attacks is crippling, so you may want to save it for higher levels when you can more easily handle that penalty. The bonus skill won't see a lot of use.

Kenku^VGTM: Nothing helpful for the Barbarian.

Kobold^VGTM: Strength penalty.

Lizardfolk^VGTM: Natural Armor and the lizardfolk's Constitution increase conflict a bit on a barbarian because Unarmored Defense and Natural Armor both provide alternatives to conventional armor, but the lizardfolk still makes a fun barbarian.

Orc^VGTM: Aggressive is cool, but the half-orc is considerably better than the full orc.

Tabaxi^VGTM: Nothing helpful for the Barbarian.

Tiefling: Nothing helpful for the Barbarian.

Asmodeus^MToF: Nothing helpful for Barbarians.
Baalzebul^MToF: Nothing helpful for Barbarians.
Dispater^MToF: Nothing helpful for Barbarians.
Fierna^MToF: Nothing helpful for Barbarians.
Glasya^MToF: Nothing helpful for Barbarians.
Levistus^MToF: Nothing helpful for Barbarians.
Mammon^MToF: Nothing helpful for Barbarians.
Mephistopheles^MToF: Nothing helpful for Barbarians.
Zariel^MToF: Legacy of Avernus has some neat spells, and the Strength increase is nice, but that's not enough to make this a useful option.
Variant: Feral^SCAG: Nothing helpful for Barbarians.
Variant: Devil's Tongue^SCAG: Nothing helpful for Barbarians.
Variant: Hellfire^SCAG: Nothing helpful for Barbarians.
Variant: Vanilla^PHB: Nothing helpful for Barbarians.
Variant: Winged^SCAG: Nothing helpful for Barbarians.

Tortle^TP: +2 Strength and 17 natural armor is fantastic for a Barbarian. With a solid source of AC, you don't need to worry about Dexterity, especially at low levels before you've picked up multiple Ability Score Increases. Survival proficiency is nice, too.

Triton^VGTM: The ability increases are decent, but the triton's other racial traits don't do much for the barbarian.

Yuan-Ti Pureblood^VGTM: Nothing helpful for the Barbarian.

Setting-specific races are address below. Not every setting allows every race, and while most races presented in the core rules and in content for the Forgotten Realms can be used in other settings, races specific to settings like Ravnica aren't typically allowed in other settings. Talk to your DM about what races are allowed in your game.

Races of Ravnica

Centaur^GGTR: The Strength increase is a great start, and Charge is fantastic on a barbarian. If you rage before charging, the hoof attack is an extra opportunity to apply your Rage bonus to damage, not to mention your crazy Strength bonus.

Goblin^GGTR: See above.

Loxodon^GGTR: The Constitution increase is great, but Natural Armor will hopefully be overridden by Unarmored Defense, and the Loxodon has very little else to contribute to the Barbarian.

Minotaur^GGTR: Minotaurs are absolutely perfect barbarians. The ability increases are fantastic. Goring Rush gets you the most important part of the Charger feat, and Hammering Horns gets you the most important part of the Shield Master feat without requiring a shield.

Simic Hybrid^GGTR: With the flexible ability increase in Strength, the Simic Hybrid is an interesting and versatile option for the Barbarian. The first round of Animal Enhancement gets you some utility options which the Barbarian has no way to replicate, and the second offers several appealing combat options which will nicely complement your class features.

Vedalken^GGTR: Nothing helpful for the Barbarian.

Skills

Animal Handling (Wis): Not really helpful for the function of the Barbarian, but the flavor makes sense.
Athletics (Str): The only Strength-based skill, Athletics is more than climbing and swimming. You use Athletics for grappling and for pushing enemies, both of which can be excellent options for Barbarians.
Intimidation (Cha): If you're built with a bit of Charisma for the Berserker's Intimidating Presence, you can be good at Intimidate. Otherwise, skip it.
Nature (Int): Intelligence is a dump stat for Barbarians, but if no one in the party has access to Nature it's not an awful choice.
Perception (Wis): One of the most important skills in the game. At least two people in the party should have it, but more is always better.
Survival (Wis): Adventuring tends to involve a lot of wandering around in untamed wilderness, so Survival can be very helpful to your party.

Background

This section does not address every published background, as doing so would result in an ever-growing list of options which don't cater to the class. Instead, this section will cover the options which I think work especially well for the class, or which might be tempting but poor choices. Racial feats are discussed in the Races section, above.

Barbarians can't do a lot with skills, but what skills you do want are on the Barbarian skill list. When looking for a Background, try to pick up skills which complement your existing skill proficiencies and which capitalize on your ability scores.

City Watch^SCAG: Athletics is great, but you won't get much use from Insight or the ability to speak two languages with your garbage Charisma.
Criminal^PHB: This might work for a Wolf Totem Barbarian, especially if you have a Rogue in the party who can be stealthy with you.
Folk Hero^PHB: Two skills from the Barbarian skill list, and a couple of tool proficiencies. The theme works really well for a Barbarian who made a name for himself among his tribe, then set out to do some more heroics.
Hermit^PHB: Medicine and herbalism can be useful for a Barbarian, especially if you don't have a healer in the party.
Outlander^PHB: The go-to option for Barbarians, you get two skills from the Barbarian list, and some fun stuff like proficiency with a musical instrument which you will never use.
Sailor^PHB: Great for aquatic campaigns. Two good skills from the Barbarian list, and boats!
Soldier^PHB: Somewhere between the Folk Hero and the Outlander. Two good skills from the Barbarian skill list, and some fun tool proficiencies.
Uthgardt Tribe Member^SCAG: Two important Barbarian skills, but instruments, artisan's tools, and languages are generally wasted on the Barbarian.

Feats

This section does not address every published feat, as doing so would result in an ever-growing list of options which don't cater to the class. Instead, this section will cover the backgrounds recommended in the "Quick Build" section of the class description, as well as other backgrounds which I think work especially well for the class, or which might be tempting but poor choices. The possibility of custom backgrounds also means that it is literally impossible for me to provide comprehensive analysis of every potential background in existence.

Alert^PHB: Feral Instinct does plenty on its own, so you shouldn't need this.
Charger^PHB: Great for closing to melee, but situational. If you can't get into melee range with your movement it may be better to use your action to throw some javelins.
Dual Wielder^PHB: Two-Weapon Fighting can be a good way to bring your bonus Rage damage into play more frequently, but since Two-Weapon Fighting uses your bonus action, this is a bad option for Berserker Barbarians.
Durable^PHB: Rage gives you resistance to most weapon damage, but you'll still face problems from spells, and with only medium armor the Barbarian's hit points typically rise and fall very far very quickly. Magical healing goes a long way, but much of your healing will come from your Hit Dice. Ideally your Constitution will be high enough to give you a big pool of hit points, so the Durable feat can go a really long way to keep your hit points high throughout the day.
Grappler^PHB: With the Barbarian's typically fantastic Strength, grappling can be an excellent choice.
Great Weapon Master^PHB: Barbarians are all about two-handed weapons, and Great Weapon Master offers some great options. Berserker Barbarians will find the extra attack benefit useful in fights with numerous weak enemies, allowing them to reserve their Frenzy for fights with large single enemies.
Heavily Armored^PHB: Rage doesn't function while you're wearing heavy armor.
Heavy Armor Master^PHB: Rage doesn't function while you're wearing heavy armor.
Inspiring Leader^PHB: This is generally better for more charismatic characters like Bards or Paladins, but temporary hit points are great for Barbarians. If you're building to utilize Frightful Presence, this might be worthy of consideration.
Mage Slayer^PHB: Only useful in games which feature an abnormally large number of spellcasters.
Martial Adept^PHB: One superiority die means that you might get to use your maneuvers two or three times a day at most. Feats should be more consistently useful.
Medium Armor Master^PHB: You won't be doing much stealth unless you went for Wolf Totem and have other stealthy people in your party, and the potential bonus to AC isn't enough to justify this feat on its own.
Mobile^PHB: You already get a speed boost, and Eagle totem will provide similar benefits.
Mounted Combat^PHB: Fighting while mounted can be a great option for Barbarians, and you have plenty of hit points to absorb any attacks which might target your mount.
Polearm Master^PHB: The Barbarian has very few options which require you to be within 5 ft. of a target. The base class offers Retaliation, and the Totem Warrior has a couple options (Totem Spirit (Wolf) and Totemic Attunement (Bear)), but if you're fine not relying on those options most of the time Polearm Master can be tempting. The bonus attack provided by the feat is especially interesting since you can get the damage of a two-handed weapon while still getting as many attacks as though you were using two-weapon fighting. However, there are numerous Barbarian abilities which allow you to make extra attacks as a bonus action which are already built into the class so you may find that the bonus polearm attack frequently goes unused. The ability to make an attack when something enters your reach is nice, but considering barbarians usually handle threats by charging them first you'll likely find that this benefit also rarely applies.
Resilient^PHB: Dexterity might be a good option, but certainly not before you have hit your maximum in Strength and possibly Constitution.
Savage Attacker^PHB: This is a bad feat. The largest damage die (d12), yields an average of 2 extra damage per turn. The absolute best case scenario is a half-orc berserker with Brutal Critical critting with a greataxe, but even then it's still only around 4.45 extra damage at the absolute most, and it's still limited to once per turn.
Sentinel^PHB: This is fantastic for Defender builds, and works very nicely with the Bear totem.
Shield Master^PHB: The best part of this is probably the ability to shove enemies (possibly shoving them prone) as a bonus action. Wolf totem provides a similar benefit.
Skilled^PHB: Helpful if your party has large skill gaps, but Barbarians aren't very good at skills, so your utility is severely limited.
Skulker^PHB: Even if you are in a sneaky party, you should be leaping from hiding to murder things.
Tavern Brawler^PHB: If you want to go for Grappler, this feat complements it nicely.
Tough^PHB: You need too many ability increases to make room for this feat. Instead, boost your Constitution.

Weapons

Handaxe: Your go-to option for two-weapon fighting.
Javelin: A great disposable ranged option when you're too far away to move into melee in one turn.
Greataxe: Brutal Critical means that a bigger damage die is better for you.
Greatsword: More reliable damage than the Greataxe, but not as useful with Brutal Critical.
Maul: Basically a blunt greatsword.

Armor

Multiclassing

Fighter: The Fighter's Fighting Style ability is decent if you go for two-weapon fighting, but Two-Weapon Fighting is hard since Barbarians already have several options which allow them to attack as a bonus action, allowing them to match TWF number of attacks while using a two-handed weapon. 2nd level brings Action Surge, which is fantastic on any character. At 3rd level consider the Champion archetype to pick up Improved Critical, which will double how often you get to use Brutal Critical.
Monk: Unarmored Defense abilities don't stack. You use whichever you got first, according to the official FAQ.
Rogue: A dip into Rogue for Expertise in Athletics will go a long way if you plan to use Shove or Grapple, but without the Fighter's big number of attacks Shove isn't always a great option. Cunning Action is not helpful for a Barbarian and conflicts with the numerous abilities which allow Barbarians to make attacks as a bonus action, so don't dip past first level.
Wizard: Barbarians have almost exactly opposite abilities to Wizards, so there isn't a lot of room for compatibility.

Example Build - Half-Orc Barbarian (Berserker)

Oh look, someone's using a greataxe!

This is a "Staple Build". This build is simple, and relies on options from the SRD and the Basic Rules wherever possible. If you need a functional build with nothing fancy or complicated, this is a great place to start.

This is a very simple build. Barbarians have very few decision points, and the biggest tactical decision they require in an encounter is whether or not to rage. Berserker adds the additional choice of potentially entering a Frenzy, but even that shouldn't be especially stressful.

Abilities

We'll mostly use the example ability scores described above, but we'll switch the Strength and Constitution so that we can get 16 in both after the Half-orc's racial ability score increases.

	Base	Increased
Str	14	16
Dex	14	14
Con	15	16
Int	8	8
Wis	10	10
Cha	10	10

Race

Half-Orc. Savage Attacks works great with greataxes, and I can't think of a weapon that says "barbarian" more than a greataxe. It also stacks with Brutal Critical, so you get to roll big piles of d12's at high levels.

Skills and Tools

Half-orcs get Intimidation for free, so we'll pick up Nature and Perception.

Background

Soldier. Of the limited number of options in the basic rules, Soldier is one of the best options for us. Since we already get Intimidation proficiency, we can replace the redundant proficiency with something else. We'll keep Athletics, and you can use the replacement proficiency to get Survival.

Folk Hero works equally well in terms of skills, and you can use your class skill proficiencies to get Animal Handling and Survival to turn both into open skill proficiency slots if you want something not on the Barbarian skill list.

Levels

Level	Feat(s) and Features	Notes and Tactics
1	Rage Unarmored Defense	For your starting gear, take a greataxe, two handaxes, and the explorer's pack and javelins. You don't start with armor, but with 14 Dex and 16 Con Unarmored Defense gives you 15 AC. You might buy yourself a shield, but that will mean putting down your greataxe, and you've got 15 hit points for a reason, and Rage will give you damage resistance. At this level you can only rage twice per day, but at first level adventuring days tend to be short because characters are so fragile, so you should be able to rage in most encounters.
2	Reckless Attack Danger Sense	Reckless Attack is a great ability, but obviously it comes with risks. At this level I recommend only using it in fights against powerful single foes so you're not taking repeated hits from groups of weak enemies, and even then consider raging at the same time to offset the additional damage you will inevitably take. Danger Sense is helpful for mitigating damage from AOE effects which will typically deal damage types not resisted by Rage. At this point you may have enough gold for a suit of Scale Mail, which will net you +1 AC, but after that start saving gold until you can get Half Plate.
3	Primal Path: Path of the Berserker Frenzy	Our first subclass ability is Frenzy. It's basically just better Rage, but you suffer a level of exhaustion when your rage ends. You don't want to go past two levels of exhaustion, and now that you have three rages per day that's a possibility. The combination of Frenzy and Reckless Attack is the reason greataxes are appealing for the Barbarian, so when you need to deal a bunch of damage in a hurry you can Rage, Frenzy, and use Reckless Attack to deal a whole bunch of damage in a hurry.
4	Ability Score Improvement (Strength 16 -> 18)	More Strength means more attack and more damage.
5	Extra Attack Fast Movement	5th level is an important milestone in 5e. Martial classes get Extra Attack, which roughly doubles your damage output. 5th level also requires proportionately more encounters worth of experience before you gain another level than any other level, so you're going to spend a lot of time at 5th level. Between Frenzy's extra attack and Extra Attack, you get three attacks with Advantage for a total of 6 d20 rolls, giving your probability of more than 26% to roll at least one natural 20, and every time you crit you're dealing 3d12+Str damage, which feels really satisfying.
6	Mindless Rage	Attacking a barbarian mentally is the easiest way to shut them down, so Mindless Rage is a significant defensive buff.
7	Feral Instinct	Going first feels great. It's usually not very important for barbarians because you don't need to cast a spell to alter the layout of an encounter or something, but it's still really nice.
8	Ability Score Improvement (Strength 18 -> 20)	20 Strength means that you're as strong as you'll be until you reach 20th level or find a really nice magic item.
9	Brutal Critical (1 die) Rage Damage +3	Adding another d12 roughly 25% of the time means that you're dealing something like 1.5 extra damage per turn. On average that's not much, but it feels very satisfying to roll 4d12 on a critical hit.
10	Intimidating Presence	Intimidating Presence is rarely useful because it eats your entire action. You could still Frenzy and attack as a bonus action, but I think the most likely use case for this is to begin a Rage solely for the purpose of chasing someone around and screaming at them.
11	Relentless Rage
12	Ability Score Improvement (Constitution 16 -> 18)	A Constitution increase means that your Unarmored Defense AC rises to 16, so Half Plate is still better. But you get a bunch of extra hit points, which is great.
13	Brutal Critical (2 dice)	Each greataxe hit die added by Brutal Critical adds roughly 1.5 extra damage per round on average. Between Savage Attacks and Brutal Critical, you're now rolling 4d12+Str on a critical, which feals really awesome.
14	Retaliation	Finally a good reason not to get as much AC as possible, Retaliation means that taking damage increases your damage output. Of course, but this level an AC of 17 is not safe by any stretch of the imagination, so don't go dumping your armor to try to trigger this. You won't need to.
15	Persistent Rage Rage Damage +4	Since you're a Berserker, ending a rage can carry a bigger consequence than it does for other barbarians, and effects that prevent you from acting like paralysis can force your race to end early.
16	Ability Score Improvement (Constitution 18 -> 20)	Your Unarmored Defense now matches the AC provided by half plate. Drop the armor so you're no longer suffering Disadvantage on Dexterity (Stealth) checks and wearing 40 lbs. of clothing. Of course, if you have magic armor that changes the math.
17	Brutal Critical (3 dice)	Another critical hit die, another 1.5 average damage per round. You're up to 5d12 on a critical hit now, which is pretty great,.
18	Indomitable Might	Once in a while you need to grapple, lift something, break something, etc. and by this level you already have 20 Strength, so your minimum result is 20. That's easily enough to pass normal ability check DCs, but you may lose grapple checks on very rare occasion,
19	Ability Score Improvement (Dexterity 14 -> 16)	A bump in Dexterity doesn't do much for you, but at the very least you get better initiative and +1 AC. If you don't want to increase Dexterity, this extra ability score improvement is clear indication that you have room to consider a feat.
20	Primal Champion	+2 to hit, +2 damage, minimum of 24 on all Strength checks, and +40 hit points on top of what you got just for gaining a level.