Path of the Seasoned Veteran

Even at an age beyond their years from their prime, few experienced barbarians choose to fight smart in combat instead of using brute force. These seasoned warriors let their opponents do most of the work for them, using their intelligence to strike true when their enemy least expects it. When a barbarian who follows this path rages, they hone in on their many years of war to focus on the weakest and most vulnerable part of their target to severely weaken both body and mind. 

Barbarians who fight with strategy and accuracy because of their experience can stand their ground alone, but work well in groups that provide tactical advantages without having to move far or quickly. Their older age gives them knowledge they can pass on to younger adventurers, usually giving them the status of a mentor. They commonly have many stories to tell, some from great victories and others from colossal failures that they learned from. 

Strong Use of the Mind

Starting when you choose this path at 3rd level, you use your Intelligence for melee attack rolls in combat that would require your Strength. This affects Rage at 1st level, Reckless Attack at 2nd level, Indomitable Might at 18th level, and Primal Champion at 20th level. This does not change what modifier enemies use when attacking you.

Additionally, your chances of striking critically are heightened because you know where to strike true. Your weapon attacks score a critical hit on a roll of 19–20. This range increases to a roll of 18-20 at 6th level, 17-20 at 14th level, and 16-20 at 19th level. 

However, this does NOT affect the Brutal Critical ability gained at 9th level, which still requires a Natural 20 roll to apply. 

Stationary Strategy

Beginning at 6th level, you have found the benefits of moving quickly on the battlefield just as much as remaining in one place. When you are engaged in combat and do not use movement on your turn, you have advantage on all melee attacks until the beginning of your next turn.

Never Let Down Your Guard

At 10th level, you know to never trust the safety of neither your enemy nor your surroundings and are always ready to defend yourself. You cannot be surprised, and your Initiative is increased by your choice of either your Intelligence or your Wisdom modifier. This must be chosen when you first gain this ability and cannot be changed once chosen.

Additionally, for the first round of combat, you automatically take your turn first unless the creature you are fighting is a CR or 13 or higher, and afterwards you return to your original turn order. This also takes effect during surprise rounds.

Know Thy Enemy

Starting at 14th level, you can share your experienced insight of your opponent with your allies. As a bonus action, choose an ally that is within 30 feet of you that you can see. Until the end of the encounter, the chosen ally scores a critical hit with a roll of 18-20. This effect does not affect any ally with an Intelligence of 13 or lower, or if they cannot hear you.

You can use this feature a number of times equal to half your proficiency bonus rounded down, and you regain all expended uses when you finish a long rest.

Calculated Counter

Starting at 16th level, you can use your reaction to block or counter when you are hit by a melee weapon attack. When you do so, the damage you take from the attack is reduced by 1d10 + your Intelligence modifier + your barbarian level.

If you reduce the damage to 0, you can lock the enemy's weapon into submission and do one of the following:

• You may attempt to disarm your enemy from the weapon you have subdued. Make an Initiative check against your enemy's Athletics check. Upon failure, nothing happens. Upon success, you toss the weapon in a direction of your choice 1d6 x 5 feet away from you, as part of the same reaction.
• You may attempt to counter with your own weapon. Make an attack roll against your enemy's AC. Upon failure, nothing happens. Upon succession, you successfully perform the attack and roll for normal damage. 

You can use this feature a number of times equal to half your proficiency bonus rounded down, and you regain all expended uses when you finish a long rest.

The Bigger They Are

Although larger foes have their strengths, their size usually exposes larger areas of weakness you can exploit. As a bonus action, you may make a Nature check against the creature with the target number being 10 + the creature's CR. Upon succession, for the rest of the encounter, you may add extra damage to your melee attacks. The damage is equal to your Intelligence (not your Intelligence modifier) x the amount of sizes the creature is larger than you.