I must say I am surprised not to see Monk on your melee-who’s-who list.
Monk doesn't seem very good to me. They have decent but not amazing offense, and poor defense. Let's look at level 5. I'll assume point build, and the following characters:
Half-orc Bear Token Barbarian, Str 18, Dex 14, Con 16, Int 8, Wis 12, Cha 8. HP 55, AC 16 (Breastplate), Attack +8/1d12+5 (+1 Greataxe), Bear Totem; rage 3x/day, +2 damage
Wood Elf Battlemaster Fighter, Str 12, Dex 18, Con 14, Int 10, Wis 14, Cha 10, HP 44, AC 18 (Breastplate, Shield), Attack +8/1d8+7 (+1 Rapier)
Wood Elf Champion Fighter, Str 12, Dex 18, Con 14, Int 10, Wis 14, Cha 10, HP 44, AC 18 (Breastplate, Shield), Attack +8/1d8+7 (+1 Rapier)
Wood Elf Hunter Ranger, Str 10, Dex 18, Con 14, Int 10, Wis 16, Cha 8, HP 44, AC 18 (Breastplate, Shield), Attack +8/1d8+7 (+1 Rapier)
Wood Elf Monk, Str 10, Dex 18, Con 14, Int 10, Wis 16, Cha 8, HP 38, AC 17, Attack +8/1d8+5 (+1 staff), +7/1d6+4 (unarmed)
Okay, let's look at offense. We'll assume a target that is AC 15 (so 70% hit chance)
Half-orc Bear Token Barbarian: 1.4 hits per round, 50% chance to be raging, 17.5 net dpr. Using reckless attack increases this to 22.75.
Wood Elf Battlemaster Fighter: 1.4 hits per round, 16.1 raw DPR. Assuming 8 rounds of combat per short rest, superiority dice add +2.25 average dpr (plus status effects that I'm ignoring at the moment), action surge adds +2 average dpr, final total 20.35 net dpr.
Wood Elf Champion Fighter: 1.4 hits per round, 16.1 raw DPR. +0.1 crits per round adds +0.45 dpr, action surge adds +2.05 dpr, final total 18.6 net dpr.
Wood Elf Hunter Ranger, 1.4 hits per round, 16.1 raw DPR, assume 50% chance for Hunter's Mark being active for +2.45 dpr, assume 0.7 hits from Colossus Slayer for +3.15 dpr, final total 21.6 net dpr.
Wood Elf Monk: 1.4 weapon hits per round (13.3), +0.65 unarmed hits per round, +0.41 unarmed hits from flurry (+7.95), final total 21.25 net dpr.
Okay, the monk is on the high end for damage and applies slightly more status effects than the battlemaster, but there really isn't an awful lot of difference in there except the champion is kinda bad. Now let's look at defense. We'll assume enemies have attack +6
Half-orc Bear Token Barbarian: 55% chance to be hit, 50% to be raging, so overall takes 41% damage, eHP 134. If reckless, chance to be hit is 80%, eHP drops to 92.
Wood Elf Fighter (either): 45% chance to be hit, eHP 98. If we add a second wind to that, eHP 118.
That's certainly one way to look at it. I'm no monk expert but I'm guessing that this metric would be one that monk specialists would disagree with. It seems that you are weighting more for a tank playstyle based on armor choice and subclass, yet you are only factoring in flurry of blows for ki point usage. The damage adjustment for this is only .41, would factoring in fewer flurries for more defensive minded dodges and disengages bump your estimation up on the effective HP?
The monk doesn't seem to be built for tanking either, it's more of a striker. Using the superior mobility and multiple attacks to disrupt opposing mages and archers. Archers may have reasonable melee attacks but mages don't always have answers and spells like Shocking Grasp and Heat Metaljust aren't as effective against monks as many of the other options that you mentioned.
Deflecting missiles wasn't taken into account, and I'll be honest I don't know if that's an oversight on your part or an indictment of the ability.
Finally, Stunning Strike has to improve the monk's survivability. This should be factored into the eHP somehow. The DC 14 con save (using your parameters) may not be lights out and not as effective against the brutes in a melee scrum that a tank would encounter, but the mages and archers that the striker would be disrupting aren't likely to have significant con saves on a regular basis.
Perhaps your in the same boat as me and can't evaluate some of those abilities as well as you'd like. Perhaps you've discounted the other factors that I mentioned because you don't feel like they provide enough oomph. Perhaps it's simply a matter of looking at the class in a role that it's ill suited to fill and discounting it as a melee class because of it. Or perhaps you're right on the money and I don't have enough experience with them to evaluate them properly. I'm interested to see what kind of rebuttals come in.
When you do the math, doubling your chance of getting a crit (if you use the RAW way to calculate crit damage) is only about a ~2% increase in damage output. It feels and sounds better and more exciting than it does if you just look at the math. But that's not bad at all, assuming your group isn't primarily a wargaming, min/max, combat-focused type of group.
So in general, I'd say that allowing a player to trade a normal class feature for something like that would be totally fine, and I just wouldn't tell them that it's not as great as they expect. They'd probably be quite happy with the outcome - it feels great and exciting, even if the math shows there's stronger options! :) Cause who doesn't like getting a crit twice as often?
I disagree with some previous commenters. I think that giving this ability via magic item would be totally appropriate - just be aware that they probably aren't getting a different magic item (e.g. an enchanted weapon) instead, unless they spend their hard-won gold on it. I can think of other magic items that are notably more powerful. For example, luckstones, cloaks of protection, or cloaks of elvenkind. And those aren't even crazy rare. But a +1 to AC (5% less damage taken) or saving throws (5% fewer saving throws failed) or advantage on checks to hide, etcetera, can be super strong in the right hands. Double the crits (~2% increase in damage output, but feels awesome) is relatively comparable.
According to Mike Mearls, it can be a really good sign in game design if you have something that feels almost OP, but you can mathematically prove it isn't.
I must say I am surprised not to see Monk on your melee-who’s-who list.
Monk doesn't seem very good to me. They have decent but not amazing offense, and poor defense. Let's look at level 5. I'll assume point build, and the following characters:
Half-orc Bear Token Barbarian, Str 18, Dex 14, Con 16, Int 8, Wis 12, Cha 8. HP 55, AC 16 (Breastplate), Attack +8/1d12+5 (+1 Greataxe), Bear Totem; rage 3x/day, +2 damage
Wood Elf Battlemaster Fighter, Str 12, Dex 18, Con 14, Int 10, Wis 14, Cha 10, HP 44, AC 18 (Breastplate, Shield), Attack +8/1d8+7 (+1 Rapier)
Wood Elf Champion Fighter, Str 12, Dex 18, Con 14, Int 10, Wis 14, Cha 10, HP 44, AC 18 (Breastplate, Shield), Attack +8/1d8+7 (+1 Rapier)
Wood Elf Hunter Ranger, Str 10, Dex 18, Con 14, Int 10, Wis 16, Cha 8, HP 44, AC 18 (Breastplate, Shield), Attack +8/1d8+7 (+1 Rapier)
Wood Elf Monk, Str 10, Dex 18, Con 14, Int 10, Wis 16, Cha 8, HP 38, AC 17, Attack +8/1d8+5 (+1 staff), +7/1d6+4 (unarmed)
Okay, let's look at offense. We'll assume a target that is AC 15 (so 70% hit chance)
Half-orc Bear Token Barbarian: 1.4 hits per round, 50% chance to be raging, 17.5 net dpr. Using reckless attack increases this to 22.75.
Wood Elf Battlemaster Fighter: 1.4 hits per round, 16.1 raw DPR. Assuming 8 rounds of combat per short rest, superiority dice add +2.25 average dpr (plus status effects that I'm ignoring at the moment), action surge adds +2 average dpr, final total 20.35 net dpr.
Wood Elf Champion Fighter: 1.4 hits per round, 16.1 raw DPR. +0.1 crits per round adds +0.45 dpr, action surge adds +2.05 dpr, final total 18.6 net dpr.
Wood Elf Hunter Ranger, 1.4 hits per round, 16.1 raw DPR, assume 50% chance for Hunter's Mark being active for +2.45 dpr, assume 0.7 hits from Colossus Slayer for +3.15 dpr, final total 21.6 net dpr.
Wood Elf Monk: 1.4 weapon hits per round (13.3), +0.65 unarmed hits per round, +0.41 unarmed hits from flurry (+7.95), final total 21.25 net dpr.
Okay, the monk is on the high end for damage and applies slightly more status effects than the battlemaster, but there really isn't an awful lot of difference in there except the champion is kinda bad. Now let's look at defense. We'll assume enemies have attack +6
Half-orc Bear Token Barbarian: 55% chance to be hit, 50% to be raging, so overall takes 41% damage, eHP 134. If reckless, chance to be hit is 80%, eHP drops to 92.
Wood Elf Fighter (either): 45% chance to be hit, eHP 98. If we add a second wind to that, eHP 118.
One of the key (ki?) features of monks is that at higher levels (definitely not level 5) they get immunity to poison, proficiency in all saving throws, and the Evasion feature (half/no damage on Dex saves that would normally do full/half). Which offsets a nominally low AC. Let's do the math of by how much.
(7th level) The monster equivalent of Evasion is called Avoidance (e.g. demilich). The DMG says this is essentially a +1 AC.
(10th level) Immunities. Being immune to one damage type doesn't matter that much for effective AC/hit points. It's useful in specific situations. But when it's useful, it's very useful, given that poison is one of the most common damage types you'll encounter in almost any adventure. Well, not including bludgeoning/piercing/slashing. I'd say fire and necrotic are also up there.
(14th level) Number of saving throw proficiencies also affects effective AC. "A monster with three or more saving throw bonuses has a significant defensive advantage, so its effective AC (not its actual AC) should be raised when determining its challenge rating. If it has three or four bonuses, increase its effective AC by 2. If it has five or more bonuses, increase its effective AC by 4." Monks are proficient in all saving throws, so they essentially get a +4 AC from that feature.
Now then. These features aren't in effect at 5th level. Yes, the monk may be effectively weaker as a combat class at level 5, but when you do the math, they're actually stronger than fighters in Tier 1 (at least, the last time I did the math that was the case, and I used Standard Array). As levels increase, monk defenses catch up, especially at 14th level.
But. Deflect Missles, a 3rd level feature. The DMG does not provide a description for how this affects effective AC or Hit points, not that I saw. Any time the monk is hit by a ranged weapon attack (e.g. bows, slings, crossbows) it can use its reaction to reduce the damage by 1d10 + Dex mod + Monk level. For the 5th level monk in your example, that's a 1d10 + 9 damage reduction, once per round, when the monk would receive damage from a ranged weapon. Ranged weapons aren't as common as melee weapons, but this is undeniably very useful and increases the effective Hit Points of the monk by a non-negligible amount. Hard to calculate for, though.
Now then. These features aren't in effect at 5th level. Yes, the monk may be effectively weaker as a combat class at level 5, but when you do the math, they're actually stronger than fighters in Tier 1 (at least, the last time I did the math that was the case, and I used Standard Array).
A monk hits about the same as a 2 weapon style fighter at level 1 (so considerably harder than dueling or great weapon), and chi points at level 2 are a bit stronger than action surge (superiority dice at level 3 are better than anything the monk gains at level 3). However, the fighter is a lot tougher, between d10s instead of d8s, second wind, and for a dueling fighter, using a shield (we won't even get into variant humans with feats). Monks have some nice features, but they really aren't top tier front line combatants (I haven't really done the math for tier 3 and 4, so maybe at those levels).
This was super helpful. I'm careful with magic item balance in my games and was considering this for a personal arc weapon reward for my player's blood hunter. Thanks for running the math!
I’m pretty certain the Sword of Kas has this ability but it’s an artifact tier magic item. I definitely agree with some that it should be a limited use (1/day or something) or it needs to be built up to as the character progresses in levels
It's really up to you. You could make it a feat or you could make it a magic item. Raising a 5% chance of a critical to a 10% chance is a pretty significant boost.
That's certainly one way to look at it. I'm no monk expert but I'm guessing that this metric would be one that monk specialists would disagree with. It seems that you are weighting more for a tank playstyle based on armor choice and subclass, yet you are only factoring in flurry of blows for ki point usage. The damage adjustment for this is only .41, would factoring in fewer flurries for more defensive minded dodges and disengages bump your estimation up on the effective HP?
The monk doesn't seem to be built for tanking either, it's more of a striker. Using the superior mobility and multiple attacks to disrupt opposing mages and archers. Archers may have reasonable melee attacks but mages don't always have answers and spells like Shocking Grasp and Heat Metaljust aren't as effective against monks as many of the other options that you mentioned.
Deflecting missiles wasn't taken into account, and I'll be honest I don't know if that's an oversight on your part or an indictment of the ability.
Finally, Stunning Strike has to improve the monk's survivability. This should be factored into the eHP somehow. The DC 14 con save (using your parameters) may not be lights out and not as effective against the brutes in a melee scrum that a tank would encounter, but the mages and archers that the striker would be disrupting aren't likely to have significant con saves on a regular basis.
Perhaps your in the same boat as me and can't evaluate some of those abilities as well as you'd like. Perhaps you've discounted the other factors that I mentioned because you don't feel like they provide enough oomph. Perhaps it's simply a matter of looking at the class in a role that it's ill suited to fill and discounting it as a melee class because of it. Or perhaps you're right on the money and I don't have enough experience with them to evaluate them properly. I'm interested to see what kind of rebuttals come in.
When you do the math, doubling your chance of getting a crit (if you use the RAW way to calculate crit damage) is only about a ~2% increase in damage output. It feels and sounds better and more exciting than it does if you just look at the math. But that's not bad at all, assuming your group isn't primarily a wargaming, min/max, combat-focused type of group.
So in general, I'd say that allowing a player to trade a normal class feature for something like that would be totally fine, and I just wouldn't tell them that it's not as great as they expect. They'd probably be quite happy with the outcome - it feels great and exciting, even if the math shows there's stronger options! :) Cause who doesn't like getting a crit twice as often?
I disagree with some previous commenters. I think that giving this ability via magic item would be totally appropriate - just be aware that they probably aren't getting a different magic item (e.g. an enchanted weapon) instead, unless they spend their hard-won gold on it. I can think of other magic items that are notably more powerful. For example, luckstones, cloaks of protection, or cloaks of elvenkind. And those aren't even crazy rare. But a +1 to AC (5% less damage taken) or saving throws (5% fewer saving throws failed) or advantage on checks to hide, etcetera, can be super strong in the right hands. Double the crits (~2% increase in damage output, but feels awesome) is relatively comparable.
According to Mike Mearls, it can be a really good sign in game design if you have something that feels almost OP, but you can mathematically prove it isn't.
One of the key (ki?) features of monks is that at higher levels (definitely not level 5) they get immunity to poison, proficiency in all saving throws, and the Evasion feature (half/no damage on Dex saves that would normally do full/half). Which offsets a nominally low AC. Let's do the math of by how much.
(7th level) The monster equivalent of Evasion is called Avoidance (e.g. demilich). The DMG says this is essentially a +1 AC.
(10th level) Immunities. Being immune to one damage type doesn't matter that much for effective AC/hit points. It's useful in specific situations. But when it's useful, it's very useful, given that poison is one of the most common damage types you'll encounter in almost any adventure. Well, not including bludgeoning/piercing/slashing. I'd say fire and necrotic are also up there.
(14th level) Number of saving throw proficiencies also affects effective AC. "A monster with three or more saving throw bonuses has a significant defensive advantage, so its effective AC (not its actual AC) should be raised when determining its challenge rating. If it has three or four bonuses, increase its effective AC by 2. If it has five or more bonuses, increase its effective AC by 4." Monks are proficient in all saving throws, so they essentially get a +4 AC from that feature.
Now then. These features aren't in effect at 5th level. Yes, the monk may be effectively weaker as a combat class at level 5, but when you do the math, they're actually stronger than fighters in Tier 1 (at least, the last time I did the math that was the case, and I used Standard Array). As levels increase, monk defenses catch up, especially at 14th level.
But. Deflect Missles, a 3rd level feature. The DMG does not provide a description for how this affects effective AC or Hit points, not that I saw. Any time the monk is hit by a ranged weapon attack (e.g. bows, slings, crossbows) it can use its reaction to reduce the damage by 1d10 + Dex mod + Monk level. For the 5th level monk in your example, that's a 1d10 + 9 damage reduction, once per round, when the monk would receive damage from a ranged weapon. Ranged weapons aren't as common as melee weapons, but this is undeniably very useful and increases the effective Hit Points of the monk by a non-negligible amount. Hard to calculate for, though.
https://www.dndbeyond.com/sources/dmg/dungeon-masters-workshop#MonsterFeatures
A monk hits about the same as a 2 weapon style fighter at level 1 (so considerably harder than dueling or great weapon), and chi points at level 2 are a bit stronger than action surge (superiority dice at level 3 are better than anything the monk gains at level 3). However, the fighter is a lot tougher, between d10s instead of d8s, second wind, and for a dueling fighter, using a shield (we won't even get into variant humans with feats). Monks have some nice features, but they really aren't top tier front line combatants (I haven't really done the math for tier 3 and 4, so maybe at those levels).
This was super helpful. I'm careful with magic item balance in my games and was considering this for a personal arc weapon reward for my player's blood hunter. Thanks for running the math!
I’m pretty certain the Sword of Kas has this ability but it’s an artifact tier magic item. I definitely agree with some that it should be a limited use (1/day or something) or it needs to be built up to as the character progresses in levels
a VERY significant boost
Butcher's Bib expands the crit range for slashing weapons.