Blood is both a weapon and a shield for those who walk the path of the Blood Knight. These warriors forge a bond with their own life force, channeling it to fuel their combat prowess and protect their allies. With each drop of blood spilled—whether their own or that of their foes—they draw closer to their full potential, tapping into a primal, relentless power that few can withstand. Blood Knights walk a razor-thin line between life and death, embracing pain and turning it into strength. To them, every wound is an opportunity, every heartbeat a drumbeat in the symphony of battle.

Vitae

When you choose this archetype at 3rd level, you learn crimson arts that are fueled by special dice called Vitae.

Vitae. You gain a pool of d10s equal to your Constitution modifier known as Vitae. These can be used to power your Blood Knight features and abilities.

You gain another Vitae at 7th level and one more at 15th level.

Saving Throws. Some of your Crimson Arts require your target to make a saving throw to resist the Crimson Arts' effects. The saving throw DC is calculated as follows:

The DC for your Blood Knight features is equal to 8 + your Constitution modifier + your Proficiency Bonus

Gore Armament

At 3rd level, you can bind yourself to a weapon with a blood ritual. Choose a melee weapon in your possession and spend one hour performing the ritual. This weapon becomes your Gore Armament, tied to your essence through blood. While bound, you can summon it to your hand as a bonus action if it is within 60 feet of you, and it cannot be wielded by others without your permission.

While a weapon is your Gore Armament, you may expend a Vitae to add your Constitution modifier to the damage rolls of the weapon for 1 minute.

Your Gore Armament remains bound to you until you perform the ritual again on a different weapon or you die. 

Crimson Arts

Also at 3rd level, you gain access to Crimson Arts, potent techniques fueled by your own vitality. You learn two Crimson Arts of your choice. Each time you level up in this class, you may replace one Crimson Art you know with another one from the list. You learn additional Crimson Arts at 7th, 10th, and 15th levels.

 

Blood Leech

When an enemy within 10 feet of you takes damage from an attack, you may use your Reaction to expend 2 Vitae. You regain hit points equal to half the damage taken. 

Blood Surge

Before making a weapon attack roll, you may expend 1 Vitae and add the result to your attack roll. The Vitae is expended whether the attack hits or misses. 

Crimson Rebuke

When you take damage, you may use your reaction to expend 1 to 5 Vitae and emit a burst of blood magic. Each creature of your choice within 10 feet must succeed on a Constitution saving throw or take 2d6 necrotic damage per Vitae spent. 

Hemorrhage

As a bonus action, you can expend 1 Vitae to force a target within 10 feet to make a Constitution saving throw. On a failure, the creature takes additional necrotic damage equal to the result of the die and begins to bleed out for 1 minute. At the start of its next turn, the creature takes necrotic damage equal to one roll of your Vitae + your Constitution modifier. The creature can repeat the saving throw at the end of each of its turns, ending the effect on a success. Alternatively, magical healing stops the effect entirely. 

Retaliatory Strike

When a creature hits you with a melee attack, you can use your reaction to expend one Vitae and make a single melee weapon attack with your Gore Armament against that creature. 

Sanguine Strike

As a bonus action, you may spend 1 to 5 Vitae. Your next successful weapon attack with your Gore Armament before the end of your turn deals an additional 2d8 necrotic damage per Vitae spent. You regain half the total damage dealt as temporary hit points. 

Surge of Vitae

At 7th level, your body adapts to the Crimson Arts, and the flow of your blood sharpens your battle instincts. You add your Constitution modifier to your initiative rolls.

You now replenish your Vitae pool on a short or long rest.

Additionally, once per day, you may use an action to regain a number of spent Hit Dice equal to your proficiency bonus.

Blood Guard

At 10th level, you can conjure a protective armor made of your own blood, bolstering your defense.

As a bonus action, you can expend 2 to 6 Vitae to cover yourself in a Blood Guard, a blood-forged armor that lasts for 1 minute.

While Blood Guard is active, you gain temporary hit points equal to the result of the die + your Constitution modifier. While these temporary hit points persist, you can choose one of the following benefits for every 2 Vitae spent:

• Your AC is increased by 2.
• You gain resistance to nonmagical bludgeoning, piercing, and slashing damage.
• You gain advantage on effects (spells, magical, or nonmagical) that would inflict a condition on you.

Hemalurgic Regeneration

At 15th level, your command over your blood bolsters your natural regeneration. Whenever you expend Hit Dice to regain hit points during a short rest, you can treat rolls that are lower than your Constitution modifier as equal to your Constitution modifier.

Additionally, when you do not spend Hit Dice to regain hit points over a short rest. You instead regain a number of Hit Dice equal to your Proficiency Bonus. You can only benefit from this feature this way twice per long rest. 

Bloodbound Aegis

At 18th level, you unlock the ultimate power of your blood, forging an invulnerable aegis to protect you.

As an action, you can expend 5 Vitae to enter a state of heightened vitality for 1 minute. While in this state, you gain the following benefits:

• You gain resistance to damage from all sources.

• Whenever you hit a creature with your Gore Armament, you deal an additional 1d10 necrotic damage.

• Whenever you regain hit points, you regain an additional amount equal to 1d10 + your Constitution modifier.

Once you use this feature, you cannot do so again until you complete a long rest or spend 10 Vitae to use it again.