D&D 5E When is it OK to let a player substitute one skill for another?

[Bacon Bits]

I'm not sure what to call it, but I see this mess all the time.

• Is it OK if use Intimidate instead of Diplomacy?
• Can I use Acrobatics to initiate a grapple?
• I worship the god of magic. Can I roll Arcana instead of Religion?
• If I scavenge some vines, is it OK to roll Survival instead of tool proficiency to make rope?

Do you just increase the DC for using an "off" skill? Do you give the player a hard "no" when it's too preposterous? How do you go about adjudicating these sort of questions?

(Comic for illustrative purposes.)

For the first example, I think it's okay for a player to expand on how they're trying to accomplish a goal. Say the player describes that they're going to take some physical action like jumping from one heaving deck of a ship to another, and you call for an Acrobatics check. It's alright for the player to say, "No, I'm trying to do this with main strength. I don't care if I'm elegant or balanced in doing it or if I land on my feet. I just want to throw myself and get over there. I want to try to do it with Athletics instead of Acrobatics." Then the DM can consider if that's reasonable, and either accept it or instead explain that what they're describing isn't possible. It's definitely going to affect the outcome, but it's perfectly acceptable play. Here, a player could say, "No, I'm not trying to be nice and convince them I'm right. I'm trying to threaten them and convince them it'll be more trouble to disagree than it's worth."

For the second example, I think if I were DM I would not allow it. I would say, "That's not how that works." Grappling is a martial action, not a skillful action. I might be convinced to allow it with disadvantage, but it would have to be pretty unusual circumstances or a particularly good idea.

For the third example, it would depend entirely on whether or not the subject of the knowledge check could reasonably be associated with their study. I think it's reasonable if they PC has an established background of studying magic in the context of worshipping a god of magic, but it doesn't seem very likely and wouldn't cover all possible Religion checks. I would be much more likely to allow a Religion check in exchange for an Arcana check if you worshipped the god of magic. Even then, however, it wouldn't be a universal substitution.

For the final example, I don't see why not. Making a rope by lashing and entwining vines is fairly reasonable, and the only tool required to do so would be something to secure the end of the rope to.

In some cases the DC may be adjusted, or I might apply advantage or disadvantage. The idea of a skill check is to decide the most appropriate thing to use based on the description the player makes of what their character is doing or based on the background of the character. If the player thinks the DM's understanding is wrong, there's no reason the player shouldn't communicate that and the DM should be open to adjustments.

 

[Ringtail]

Whenever it sounds like fun.

This is usually my go-to solution. Using the listed examples, I think using Survival to turn vines into rope is an excellent and creative use of survival. I also personally use Investigation and Perception (5e) interchangeably when it comes to finding traps. (This one in my experience is a common cause for debate.)

The only line I draw is Intimidation vs Diplomacy/Persuasion. If a player says "I'm going to try and use Persuasion" and then threatens to kill the NPC if they don't divulge the information, I'm going to put my hand up and say "Wait, that's Intimidation. Either roll Intimidation or change what you say." You don't have to be a great actor, I'll let you summarize if you can't think of a great line but there is a big difference between Intimidating someone into submission or persuading them to be helpful.

 

[Weiley31]

I see nothing wrong with it: just, as mentioned before by other posters, keep in mind that an Intimidation skill usage may produce different result/reaction/favorability compared to using say Bluff or Persuasion.

 

[Deset Gled]

I prefer to let the player’s description of what’s going on narratively dictate what’s going on narratively. But to each their own.

My rule usually is "Tell me what you want to do, and I'll tell you what skill and ability that will fall under".

Quoting two different people here because multiple people have voiced this and I don't want to single out anyone in particular...

As a player, I get to choose what skill I use. I am here to play a game, not just listen to your story. My character has abilities. I want to use those abilities.

I can't simply narrate to you what my CHA 18 Half Elf with Proficiency and Advantage will say to convince the local sheriff to let us through town. Because I'm not a CHA 18 Half Elf with Proficiency and Advantage in Diplomacy. But I can tell you what skill I want to use (Diplomacy or Intimidation) and what the result of the roll is. From there, we can work out the results together.

You are free to tell me that starting an Intimidate check counts as an automatic failure at Diplomacy, and that I'll have to live with the consequences of my roll. You decide that the equivalent Arcana check has a DC that's 15 points higher than the matching Religion check. You can tell me that my Survival roll is straight up ineffective at making rope without tools. But you don't get to tell me what skill my character is using, any more than you get to decide what weapon he's attacking with or what spell he's casting.

 

[iserith]

As a player, I get to choose what skill I use.

You expressly don't according to the rules of D&D 5e. You can ask if a proficiency applies to an ability check the DM has already called for, but that's it. The DM is the only one who can decide whether or not an ability check is called for based on his or her determination of the uncertainty of the outcome and whether there's a meaningful consequence for failure.

You don't have to play the game according to the rules as written of course. But that's how it's written.

 

[Charlaquin]

As a player, I get to choose what skill I use.

Under my house rule, yes, you do. Like I said, I let the player determine if one of their proficiencies is appropriate to an ability check I’ve called for.

I am here to play a game, not just listen to your story. My character has abilities. I want to use those abilities.

According to the section of the rules titled How To Play, the player’s role is to describe what they want to do, and the DM’s role is to determine what happens as a result, calling for a dice roll if necessary to resolve uncertainty in the outcome (I’m paraphrasing, but that’s the gist of it.)

Furthermore, it seems to me that asking to make dice rolls is not an optimal strategy, as dice rolls have a chance of failure. Describing an action with the goal of achieving success without a roll would seem the better approach to me, and then your character’s skills serve as insurance against failure in the event that you do have to make a roll.

I can't simply narrate to you what my CHA 18 Half Elf with Proficiency and Advantage will say to convince the local sheriff to let us through town. Because I'm not a CHA 18 Half Elf with Proficiency and Advantage in Diplomacy. But I can tell you what skill I want to use (Diplomacy or Intimidation) and what the result of the roll is. From there, we can work out the results together.

You don’t have to narrate what your character says. Simply describe what you want to accomplish and how you want to accomplish it with a reasonable degree of specificity (e.g. “I try to convince the sheriff to let us through town by explaining that we mean no harm” or whatever).

You are free to tell me that starting an Intimidate check counts as an automatic failure at Diplomacy, and that I'll have to live with the consequences of my roll. You decide that the equivalent Arcana check has a DC that's 15 points higher than the matching Religion check. You can tell me that my Survival roll is straight up ineffective at making rope without tools. But you don't get to tell me what skill my character is using, any more than you get to decide what weapon he's attacking with or what spell he's casting.

No, I determine if your action can succeed, if it can fail, and if there are consequences for failure, calling for an ability check if all of those things are true (to which you can add your proficiency bonus if you believe one of your proficiencies is applicable). Then I describe the results, which will often lead to a new decision point and start the pattern of play over from step 1.

 

[Deset Gled]

You expressly don't according to the rules of D&D 5e.

Wow, I didn't realize that was hard ruled in 5e like that. I have only been a player (not DM) in 5e, and we definitely haven't been playing like that.

 

[Charlaquin]

Wow, I didn't realize that was hard ruled in 5e like that. I have only been a player (not DM) in 5e, and we definitely haven't been playing like that.

The way you play is pretty common in my experience, but I believe it is a habit carried over from previous editions. Nothing wrong with that if it’s fun for you of course, but I find a lot of the most common problems DMs express with D&D are caused by carrying over play habits from other games.

 

[iserith]

Wow, I didn't realize that was hard ruled in 5e like that. I have only been a player (not DM) in 5e, and we definitely haven't been playing like that.

The way you're playing is certainly more in line with D&D 3.Xe and 4e so it's possible that approach carried over if some or all of your group plays or played those games. It's pretty common and the game doesn't break if you do it, but it does produce a different experience than what is probably intended by the rules as written.

 

[Rune]

Quoting two different people here because multiple people have voiced this and I don't want to single out anyone in particular...

As a player, I get to choose what skill I use. I am here to play a game, not just listen to your story. My character has abilities. I want to use those abilities.

I can't simply narrate to you what my CHA 18 Half Elf with Proficiency and Advantage will say to convince the local sheriff to let us through town. Because I'm not a CHA 18 Half Elf with Proficiency and Advantage in Diplomacy. But I can tell you what skill I want to use (Diplomacy or Intimidation) and what the result of the roll is. From there, we can work out the results together.

You are free to tell me that starting an Intimidate check counts as an automatic failure at Diplomacy, and that I'll have to live with the consequences of my roll. You decide that the equivalent Arcana check has a DC that's 15 points higher than the matching Religion check. You can tell me that my Survival roll is straight up ineffective at making rope without tools. But you don't get to tell me what skill my character is using, any more than you get to decide what weapon he's attacking with or what spell he's casting.

iserith addressed this well above, but I wanted to further add you seem to be making some assumptions about playstyle that don’t follow from the posts you quoted (or from mine, which aligns, but was not quoted).

In particular, assuming that a game that treats ability checks as descriptive of the game fiction that precedes them as a story the DM is telling is absurd. I can only speak for myself, but I can assure you, as a DM, story is not my job! My job is to provide the pieces for the players to make a story from. That has nothing to do with the order of interplay between fiction and mechanics.

To be clear, though, that interplay happens like this (in games I run and in the rules):

Narrative informs what mechanics are used to inform the resulting narrative. This has nothing to do with play-acting, nor specific detail (although neither is ruled out). It simply requires that the player be clear about their PC’s intent and their approach toward achieving it.