Rule of Cool with a Flail... what limitation should be there?

Question

So we've recently had our first D&D session, a small something I wrote a few years back. No major issues (besides half-orcs with an evil alliance helping people, but it was more of a "this is what D&D is" session than anything else).

One of the Half-Orcs, a Barbarian / Warrior (cannot remember precisely which) was wielding a Flail, and used it to attempt to rip the sword out of the hand of a goblin. He rolled a natural 20, so I figured "why not?". From then on, he attempted to do the same to other goblins / enemies.

As I believe this can be a game-breaking mechanic, what would be the best way to thwart their efforts? So far I've been telling them that they didn't steal the sword, but dealt some damage anyway ( minus a damage point, because they were aiming for the sword, not the goblin ). However, this can be a bit monotonous.

Answer 1

You have a few options:

1. You could tell your player "If you want to disarm enemies, you need to be a Battlemaster (or take the Martial Adept feat) and use the Disarming Attack manuever." This is probably the simplest option - you stick to the rules in the PHB and if that doesn't work for your player, that's just too bad.
2. You could allow the player to use the optional Disarm rule from the DMG. You can find it on page 271, and it's pretty simple to add to your game. For fairness, you should probably allow everyone to use it. Of course, this includes NPCs and monsters, so your players may find themselves wishing they'd never asked...
3. You could make up something of your own. You've already done that, really: You have a rule where the player can try to disarm with any attack, but it deals 1 less damage than normal, and only succeeds in disarming on a 20. You're not happy with this as it stands, so you might want to change it a little, or throw it away and make something new.

Just remember, it's important for everyone around the table to be having fun, and that includes you.

Answer 2

Consider a house rule: Novel improvised actions are more effective, repeat improvised actions are less effective

We've only played with this house rule for two weeks explicitly but it pretty well captures something that has been our convention for much longer. We've called it, "Show Me Something New".

New Rule: Show Me Something New

• When a character uses an improvised action that is significantly different from any improvised action taken recently they have advantage.
• When a character uses an improvised action that is too similar to an improvised action taken recently they have disadvantage.

For our table, "recently", tends to mean that session or the previous session. The effect has been for players to come up with a much greater variety of interesting actions for their turns, and for me not to have to worry about the long term consequences of establishing an action as working a particular way. In your situation this would hopefully result in the player feeling rewarded for coming up with something cool (disarming with a mace), but then encouraged to come up with something else that is cool.

Answer 3

Some excellent answers here, I only wanted to add a fun alternative, if you have the time and inclination for it:

Having creative players can be fun at first, but as you rightly observed their actions can unbalance things too far in their favour and reduce the challenge. However, in a living world, there is no reason that enemies wouldn't have their own reaction to such events. "There's a hero going around and he loves disarming his enemies."

Before you know it, all the Goblins are using leather straps to keep their weapons firmly in their hands and the next time he attempts to disarm them results in an attack of opportunity for one of the goblin's allies. Maybe even turn the tables on the party and start having enemies that try to disarm them. They could loot the strapped Goblin weapons or augment their own to deal with this challenge. Taken to the extreme, you could have a mini-arms race based on disarming and protecting against disarming.

Answer 4

If you are attempting to disarm someone, you are not trying to hurt them.

One approach is noting that being disarmed is a lot like being defeated. So when a player tries to do something that would defeat the foe if it succeeded, try this simple mechanic:

First, if the action is telegraphed (the foe saw the player do it in the past), the attack has automatic disadvantage.

Second, roll to hit as normal. If you hit, roll damage as normal. Then double the damage.

Do not apply this damage.

If the damage total exceeds the target's current HP, the "effectively defeated" effect occurs.

If it does not exceed the target's current HP, the attempt fails. Take the original damage (not doubled) and half it. You deal that much damage in your failed attempt. (This mainly exists to prevent this from slowing gameplay too much. Half damage is a huge penalty.)

"Effectively defeated" includes being disarmed, having your armor and shield ruined or damaged, knocking you off a ledge, etc. As a typical consequence, the very least, the target withdraw from combat then spend an action to recover from it, granting advantage until their turn and having to spend an action to recover from it, granting advantage until their turn and suffering an ongoing mechanical penalty afterwards (reduced damage die, etc), or some other serious penalty.

This x2 multilpier on pseudo-damage should stack with crits.

If the character has multiple attacks in one turn, allow them to use them all in the attempt to disarm (this helps prevent clerics/paladins from being head-and-shoulders better at disarming (or similar actions like this) than fighters). You might want to ask the player how many attacks they want to spend on the special attack.

The effect of this is that a foe that is nearly defeated can be defeated faster, but doing it on a non-defeated foe is inefficient. A character who knows they can reliably deal enough damage to half-kill some kind of foe could use this to very quickly cripple large numbers of them: take someone who deals 5-10 damage per hit, surrounded by 5 ~10 HP guards, who gets 5 attacks (4+bonus).

With those 5 attacks he could reliably disarm all of them (I wouldn't provide the telegraph penalty when it is all done in one round), then move away from the now far less dangerous guards without provoking meaningful OAs.

It both creates cool fiction, and isn't over powered. Using it on a 400 HP death knight isn't going to go well, unless you have figured out a way to deal 200+ damage in a round, in which case more power to you!

Answer 5

Introduce a set of actions which can be performed if a critical hit occurs, that players can perform instead of the additional damage.

A good source of pre-balanced possibilities is the list of battlemaster maneuvers, as some of them occur when you hit with a weapon attack. Remove the extra damage and keep the effects.

Disarming attack is among these options.