Knife of the Undermountain King is one of the Shortsword Weapons in Baldur's Gate 3. Knife of the Undermountain King is a powerful magical sword that makes results of 19 into critical hits and gives you a reroll on low damage rolls, it also helps against obscured targets by giving you advantage to the attack roll. In BG3, each type of weapon has different ranges, damages, and other features (Finesse, Versatile, Dippable, etc.). Characters need to master certain Proficiency before using a weapon, and sometimes gain special Actions while holding it.
Snatched from the realm of the mad wizard Halaster Blackcloak, this knife became a prized keepsake of a duergar king.
BG3 Knife of the Undermountain King Information
- Organ Rearranger: Reduce the number you need to roll a Critical Hit while attacking by1. This effect can stack. When you roll 2 damage or less, reroll the dice, taking the highest result.
- Shadow Blade: You have Advantage on Attack Rolls against Lightly or Heavily Obscured targets when using this blade.
- Range: 1.5m
BG3 Knife of the Undermountain King Location & Where to Find
- Location: Crèche Y'llek
- Merchant: A'jak'nir Jeera, Quartermistress, (1392 Gold)
- Dropped by: A'jak'nir Jeera, Quartermistress
Knife of the Undermountain King Notes & Tips for BG3
- Rarity: Very Rare
- Value: 480
- Weight: 0.9
- Despite its description, Organ Rearranger works on any attack roll, including offhand weapons, ranged attacks, and spell attack rolls, reducing the roll needed to Critically Hit by 1.
- Shadow Blade is currently bugged. When first using the weapon it works as intended, but as soon as the game is saved and reloaded the character no longer has advantage.
- 025e162a-45ec-4f4c-89da-04d8e8dfe606
- Anonymous
Does the reroll for 2 or less on your damage dye work for any weapon or spell while this is equipped or does it only apply to attacking with this weapon? Specifically thinking for Eldridge Blast as I want to boast the crit potential with that cantrip.
- Anonymous
Does this also reduce the number needed to crit on monk unarmed strikes?
- Anonymous
This item has recently been updated to reduce critical threshold of all attacks by 1, as is the case with similar effects.
Previously, this weapon simply had a 19-20 range for criticals.
- Anonymous
Is it just me or does the wording on this sword imply 19 is as low as its crit range gets? Every other item the improves crit range states it stacks but this one. Does anyone know if this weapon can crit below 19?
don’t like how much the crit build depends on unique equipment
- Anonymous
Even when bugged, this weapon is ridiculously strong. The first ability is just that good. Critting on a 19 effectively doubles your crit odds, and it stacks with other crit chance increasing items. In addition, it applies to other melee weapons and ranged weapons.
My rogue will crit on an 18, 19, and 20. And since he always attacks with advantage due to hiding the probability is increased further. It has perfect synergy with rogue, since all kinds of damage rolls will be rerolled. Sneak attack is the obvious one, it is 1d6 per two rogue levels so that is gonna be a lot of 1's and 2's that you reroll. I combine it with a ring that deals 1d4 to obscured targets and a bow that deals 1d4 to feared targets. These things add up and you'll get consistent crits with big numbers.
The advantage part is still bugged as of September 3, but it doesn't matter since the first ability is just that good. If the advantage ability also works this weapon is absolutely bonkers. Keep it equiped, even if it is just in the offhand slot.
- Anonymous
I was able to get a second copy of this weapon by killing the double of the character who had this in shar's test where you fight your clones. Not sure if that's guaranteed. I snuck around and assassinated the copy in one round, and looted him before any of the other clones were aware.
- Anonymous
The Crit Passive works on all attacks you make while it is equipped in a melee slot.
Main and Off Hand. Works on ranged weapon attacks and spell attacks.
- Anonymous
- Anonymous
Be aware that the reroll for damage dice from this is not always a good thing and can actually reduce your damage. It might be a bug, but as of version 4.1.1.3669438 when you have this weapon equipped for the reroll and are using a different weapon, the reroll loses the weapon's damage modifier.
For example;
If you have a dex mod of +4 with a dagger in your offhand, and a dmg reroll results in a roll of 3, your offhand attack will only do 3 dmg rather than 3+4. This makes it worse than simply taking the damage roll of 1 and getting 1+4.
This seems to apply to all weapons other than the Undermountain King knife itself, however it does not remove special weapon effects that add damage. The Titanstring bow for example will still apply your str mod to the damage even if it's a reroll. Likewise rerolls for attack spells like Eldritch Blast, still get the charisma modifier if applicable.
Finally, when using the reroll effect on a ranged weapon or spell attack, the combat log doesn't tell you it's a reroll like it does for melee weapons.
- Anonymous
I can't seem to use it in the off-hand, the game just won't let it be equipped there
- Anonymous
Does anyone know how this interacts with savage attacker feat? will the new roll also roll two dice and take the highest?
- Anonymous
This is the only Crit number reduction that I've seen that doesn't mention that it stacks, does that mean that it doesn't stack with things that do specify they stack?
- Anonymous
- Anonymous
This work with the items that reduce in 1 the number to bein a Crit? Like, the Crit of this Weapon is 19-20, if I have an item that reduce the number in 1, becomes 18-20?
- Anonymous
it says it grants advantage against heavily obscured targets but i didn't get advantage attacking enemies inside the darkness cloud
- Anonymous
this is great weapon for a warlock. the increased critical range on it (Crits on a 19) works on eldritch blast. would also be great in the hands of any ranged character, like a swords bard, thief rogue or gloomstalker ranger using ranged weapons. just hold it in your melee slot and enjoy the increased critical range on your ranged attacks.
Does the damage reroll effect apply to smite dice?
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