One of my players tries to be overly creative in battle, and as an inexperienced DM, I have trouble coming up with a roll or response for him.
Basically his character is a psychopath in battle.
He constantly tries to intimidate enemies into fleeing or surrendering. I had to explain that this is a full action and not something he can do freely after felling an enemy.
Recently he pulled an arm off an enemy. I had no idea what to set that DC for.
Then he tried to use that arm to demoralize more enemies, by tossing it on the ground near them (no improvise action used). I didn't feel that warranted a significant bonus (I let him pull an unconscious ally out without using 4 opportunity attacks to end the poor bard).
I don't want to stifle his creativity, but I need to know how to handle these improvised actions.
What should the DC be to remove limbs? How many enemies can be intimidates at a time? Should jumping off a roof and landing on an enemy negate or reduce fall damage? And if you can think of something similar he might try, tell me that to.
He constantly tries to intimidate enemies into fleeing or surrendering. I had to explain that this is a full action and not something he can do freely after felling an enemy.
Intimidation isn't an action, per se; it's just roleplaying. If he does something intimidating - like knocking out the toughest enemy - it's fine to let him attempt to intimidate the underlings. Creatures are allowed to utter short sentences and gesture during their turn:
Other Activity on Your Turn
Your turn can include a variety of flourishes that require neither your action nor your move.
You can communicate however you are able, through brief utterances and gestures, as you take your turn.
You can also interact with one object or feature of the environment for free, during either your move or your action. For example, you could open a door during your move as you stride toward a foe, or you could draw your weapon as part of the same action you use to attack.
If you want to interact with a second object, you need to use your action. Some magic items and other special objects always require an action to use, as stated in their descriptions.
The DM might require you to use an action for any of these activities when it needs special care or when it presents an unusual obstacle. For instance, the DM could reasonably expect you to use an action to open a stuck door or turn a crank to lower a drawbridge.
Whether this is possible at all and how hard it is depends on the enemies. It's not hard to intimidate goblins into fleeing, but hobgoblins are too proud to look weak in front of their peers. A skeleton will probably fight until destroyed, but a vampire is cunning enough to flee if it looks like it might lose.
I don't want to stifle his creativity, but I need to know how to handle these improvised actions.
The DMG has optional rules for lingering injuries, massive damage, and additional combat actions as well. You should check those out, since they might cover some of the things your player is trying to do. The lingering injury rules are nice because they're open-ended and let you give your players a cool bonus if they score a critical or reduce an enemy to 0, like breaking someone's arm.
What should the DC be to remove limbs?
You generally want to stick to DC 10 for easy tasks, DC 15 for medium, DC 20 for hard. In rare cases you can go up to DC 25 for very hard tasks and DC 30 for nearly impossible tasks.
Ripping off someone's arm is very hard. I'd set the DC at 25 and require that they have both hands free and have the enemy grappled already. That means they need at least a +5 bonus to have a chance of succeeding at all, and even then he'd need a 20. With a bit of magic or Bardic Inspiration the task becomes more feasible.
As a rule of thumb you don't want players bypassing the enemy's HP, AC and saves regularly.
How many enemies can be intimidates at a time?
As many as you think appropriate. If you're on the fence, roll some dice. Maybe one or two of the goblins are braver than most.
Should jumping off a roof and landing on an enemy negate or reduce fall damage?
I'd shave off 10 feet off the fall. Enough to jump off a low roof unharmed but not enough to jump off a tall building without taking damage.
I'd talk to your player about how you're going to handle these issues moving forward. Ideally you would've all had a conversation about the kind of game you want to play before you started, but it sounds like this is still early in your campaign. Make sure he understands that he won't be able to maim every enemy that he comes across, and that there are consequences for maiming people. If he starts ripping limbs off the town guard, he might not like what happens next. I also recommend you throw in a couple of weak enemies into some of your encounters specifically for this player to easily destroy.
I think you should lean into this. Combat in 5e can be kind of dry, but there are things you can do to fix that and make it incredibly colorful and interesting. And if you have a player who wants to have fun with it, then you can set up situations for players to take advantage of.
First of all, if you haven't looked over this article about cinematic combat stunts, I recommend giving it a look. What it boils down to is that you are giving players a way to give themselves advantage in combat by being creative and making skill checks. And since they are going to gravitate toward the skills they are best at, it means the players are going to play to their characters' strengths. If you'd like to read even more on the subject, Sly Flourish has an article about improvising combat situations. You can set the scene for this by putting interesting things in your battlefield. Trees, broken statues, fallen columns, small hills of rubble, jungle vines are all things players can use to hide behind, jump off of, drop from, etc. Just spice up the room descriptions and let the players go nuts. The crazier the idea, the harder the DC, but imagine telling someone it's nearly impossible to do something and they roll a 20. The table is going to go crazy.
Something I do when players get creative is look at the worst possible outcome from their action and then give them a DC to hit to avoid that outcome. I then apply that to a sliding scale to give them varying degrees of success/failure.
Player wants to leap off the second floor balcony and drive their pole-ax into the skull of the troglodyte below: Roll acrobatics. To hit is the necessary roll for combat, the acrobatics roll is to see how well they can aim their jump and stick their landing. Worst case scenario, they miss, land adjacent to the monster, and become prone. Jumping off the balcony is easy: DC 5. Hitting a humanoid that is fairly thick and muscular is a little harder: DC 10. Not getting tied up in flailing body parts, not getting swatted by an instinctual reaction, the creature side stepping, and other mishaps add another layer of difficulty: DC 15.
Now the player rolls, and based on the result, I give them an interpretation of their success/failure. DC 15, the roll is 18, the attempt is successful, roll hit/damage. The roll is a 9, they miss the landing, I'll give a small penalty(-2) on the to hit roll. Roll is a 20, I'll have them add the prone status to the troglodyte on a successful hit. Roll is a 1: they fail the jump, land prone and have disadvantage on their attack roll.
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For something like Intimidation, it can be an action to use but it can also be a gesture mid-combat as InquisitiveCoder pointed out. If you make it a full action then you are pretty much obligated to make every creature in the fight roll an opposed check. If you make it a free action then you can play with how many of the creatures are intimidated, making rolls for those you feel would be most affected by the gesture.
There is also something, I don't recall if the DMG covers it, called morale, and it's an amazing tool. As fights go on creatures, and players both, begin to fear death. As an invisible, to the players, tool you can start to see how the death and, in your case, dismemberment of their compatriots is affecting their willingness to stay the course and fight. A roll could be made, with an increasing DC, each time another monster dies, or you can have them run when X number of their group is dead. Either way it creates a way to make something like intimidation a very valuable tactic.
One of my players tries to be overly creative in battle, and as an inexperienced DM, I have trouble coming up with a roll or response for him.
Basically his character is a psychopath in battle.
He constantly tries to intimidate enemies into fleeing or surrendering. I had to explain that this is a full action and not something he can do freely after felling an enemy.
Recently he pulled an arm off an enemy. I had no idea what to set that DC for.
Then he tried to use that arm to demoralize more enemies, by tossing it on the ground near them (no improvise action used). I didn't feel that warranted a significant bonus (I let him pull an unconscious ally out without using 4 opportunity attacks to end the poor bard).
I don't want to stifle his creativity, but I need to know how to handle these improvised actions.
What should the DC be to remove limbs? How many enemies can be intimidates at a time? Should jumping off a roof and landing on an enemy negate or reduce fall damage? And if you can think of something similar he might try, tell me that to.
Intimidation isn't an action, per se; it's just roleplaying. If he does something intimidating - like knocking out the toughest enemy - it's fine to let him attempt to intimidate the underlings. Creatures are allowed to utter short sentences and gesture during their turn:
Whether this is possible at all and how hard it is depends on the enemies. It's not hard to intimidate goblins into fleeing, but hobgoblins are too proud to look weak in front of their peers. A skeleton will probably fight until destroyed, but a vampire is cunning enough to flee if it looks like it might lose.
The DMG has optional rules for lingering injuries, massive damage, and additional combat actions as well. You should check those out, since they might cover some of the things your player is trying to do. The lingering injury rules are nice because they're open-ended and let you give your players a cool bonus if they score a critical or reduce an enemy to 0, like breaking someone's arm.
You generally want to stick to DC 10 for easy tasks, DC 15 for medium, DC 20 for hard. In rare cases you can go up to DC 25 for very hard tasks and DC 30 for nearly impossible tasks.
Ripping off someone's arm is very hard. I'd set the DC at 25 and require that they have both hands free and have the enemy grappled already. That means they need at least a +5 bonus to have a chance of succeeding at all, and even then he'd need a 20. With a bit of magic or Bardic Inspiration the task becomes more feasible.
As a rule of thumb you don't want players bypassing the enemy's HP, AC and saves regularly.
As many as you think appropriate. If you're on the fence, roll some dice. Maybe one or two of the goblins are braver than most.
I'd shave off 10 feet off the fall. Enough to jump off a low roof unharmed but not enough to jump off a tall building without taking damage.
I'd talk to your player about how you're going to handle these issues moving forward. Ideally you would've all had a conversation about the kind of game you want to play before you started, but it sounds like this is still early in your campaign. Make sure he understands that he won't be able to maim every enemy that he comes across, and that there are consequences for maiming people. If he starts ripping limbs off the town guard, he might not like what happens next. I also recommend you throw in a couple of weak enemies into some of your encounters specifically for this player to easily destroy.
I think you should lean into this. Combat in 5e can be kind of dry, but there are things you can do to fix that and make it incredibly colorful and interesting. And if you have a player who wants to have fun with it, then you can set up situations for players to take advantage of.
First of all, if you haven't looked over this article about cinematic combat stunts, I recommend giving it a look. What it boils down to is that you are giving players a way to give themselves advantage in combat by being creative and making skill checks. And since they are going to gravitate toward the skills they are best at, it means the players are going to play to their characters' strengths. If you'd like to read even more on the subject, Sly Flourish has an article about improvising combat situations. You can set the scene for this by putting interesting things in your battlefield. Trees, broken statues, fallen columns, small hills of rubble, jungle vines are all things players can use to hide behind, jump off of, drop from, etc. Just spice up the room descriptions and let the players go nuts. The crazier the idea, the harder the DC, but imagine telling someone it's nearly impossible to do something and they roll a 20. The table is going to go crazy.
"Not all those who wander are lost"
Adding to what the others have already given you:
Something I do when players get creative is look at the worst possible outcome from their action and then give them a DC to hit to avoid that outcome. I then apply that to a sliding scale to give them varying degrees of success/failure.
Player wants to leap off the second floor balcony and drive their pole-ax into the skull of the troglodyte below: Roll acrobatics. To hit is the necessary roll for combat, the acrobatics roll is to see how well they can aim their jump and stick their landing. Worst case scenario, they miss, land adjacent to the monster, and become prone. Jumping off the balcony is easy: DC 5. Hitting a humanoid that is fairly thick and muscular is a little harder: DC 10. Not getting tied up in flailing body parts, not getting swatted by an instinctual reaction, the creature side stepping, and other mishaps add another layer of difficulty: DC 15.
Now the player rolls, and based on the result, I give them an interpretation of their success/failure. DC 15, the roll is 18, the attempt is successful, roll hit/damage. The roll is a 9, they miss the landing, I'll give a small penalty(-2) on the to hit roll. Roll is a 20, I'll have them add the prone status to the troglodyte on a successful hit. Roll is a 1: they fail the jump, land prone and have disadvantage on their attack roll.
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For something like Intimidation, it can be an action to use but it can also be a gesture mid-combat as InquisitiveCoder pointed out. If you make it a full action then you are pretty much obligated to make every creature in the fight roll an opposed check. If you make it a free action then you can play with how many of the creatures are intimidated, making rolls for those you feel would be most affected by the gesture.
There is also something, I don't recall if the DMG covers it, called morale, and it's an amazing tool. As fights go on creatures, and players both, begin to fear death. As an invisible, to the players, tool you can start to see how the death and, in your case, dismemberment of their compatriots is affecting their willingness to stay the course and fight. A roll could be made, with an increasing DC, each time another monster dies, or you can have them run when X number of their group is dead. Either way it creates a way to make something like intimidation a very valuable tactic.