Question for dm rulings.

[Traab]

Just watched a video showing how someone could create the flash in 5e. While not 100% speed potential maximized, (I was seeing potential builds that reached over 1k feet per round potentially,) it still ended up with i think 600 feet per round movement speed. As a dm, what would be your reaction to "I want to run 300 feet back and forth triggering all traps in the halls/rooms/whatevers and escaping before they can effect me" as a style of scouting? Would you let them auto avoid pit traps, dart traps, closing door traps, etc etc etc because they are moving too fast to get nailed by them? Would there be some traps you would allow that for but others would get him? I imagine his travel speed would have no effect on the end result of running into that demon mouth trap in tomb of horrors after all.

[MrStabby]

So an arrow trap is going to work fine. An arrow should be moving at about 1200 ft per round so you wont be out running that. And running was wont help your reaction time. I might cap the range it would work over though.

Given that a trap that fires an arrow (assuming same speed as a human) has an operating part that moves at least that fast this would suggest a lot of mechanical traps that try and shove something sharp into people would also work just fine.

Electricity, explosions, anything arcane/spellcasting/cursed would be fine - no dodging those.

Rolling boulders, gas that slowly fills a room, walls that close in on people... probably would struggle against you.

[Traab]

So an arrow trap is going to work fine. An arrow should be moving at about 1200 ft per round so you wont be out running that. And running was wont help your reaction time. I might cap the range it would work over though.

Given that a trap that fires an arrow (assuming same speed as a human) has an operating part that moves at least that fast this would suggest a lot of mechanical traps that try and shove something sharp into people would also work just fine.

Electricity, explosions, anything arcane/spellcasting/cursed would be fine - no dodging those.

Rolling boulders, gas that slowly fills a room, walls that close in on people... probably would struggle against you.

Its not so much the travel speed of the arrows as the time it takes from hitting the trigger to setting it off and said arrows being aimed at where a standard player would be standing. Think indiana jones and the rolling boulder temple he raided. In one section (https://youtu.be/mC1ikwQ5Zgc?t=105) he dodged the dart traps because he was sprinting full out to escape and who is crazy enough to SPRINT through a trap filled ruin?! No wonder they werent aimed right to nail him. This would be a more advanced version of that due to better traps, but also a guy running about 20x faster than indiana. I just did a quick scan and it seems like dart traps and such are built along those lines, single trigger, single dart path. If a single trigger filled the entire room with darts that would be another matter. I agree that at least some magic traps, namely always on traps, like anyone entering a room is hit by a hold person spell automatically, or there is a mist in the room that forces an int save or you get feebleminded or whatever wouldnt be avoided by a full sprint, but again, trigger traps, unless they effect the whole room at once, just seem like they wouldnt have the chance to effect something moving that quickly.

To go back to the dart trap for a moment, this is what I got from a quick google for 5e traps.
The trap activates when more than 20 pounds of weight is placed on the pressure plate, releasing four darts. Each dart makes a ranged Attack with a +8 bonus against a random target within 10 feet of the pressure plate (vision is irrelevant to this Attack roll). (If there are no Targets in the area, the darts don’t hit anything.) Basically, unless that dart reaches him in less than .1 seconds of him hitting the trigger, its going to miss. He is traveling about 100 feet per second. That was the main reason I called for a ruling. Mechanical triggers traps, unless they trigger something with a wide area of effect, shouldnt work on someone moving that fast. Pit traps would probably work though as thats the floor dropping out from under him all at once.

[Samayu]

As a DM, you can fall back on the rules. And the rules say if you step there you trigger the trap and will take damage if you fail your save.

But I think that moving at the speeds you mention is a crazy thing that the rules somehow allow. I would not compound this craziness by pretending that this supernatural speed allows you to do things that the rules don't allow. Just say, "yeah, that speed is weird, but the rules allow it."

[Unoriginal]

Just watched a video showing how someone could create the flash in 5e. While not 100% speed potential maximized, (I was seeing potential builds that reached over 1k feet per round potentially,) it still ended up with i think 600 feet per round movement speed. As a dm, what would be your reaction to "I want to run 300 feet back and forth triggering all traps in the halls/rooms/whatevers and escaping before they can effect me" as a style of scouting? Would you let them auto avoid pit traps, dart traps, closing door traps, etc etc etc because they are moving too fast to get nailed by them? Would there be some traps you would allow that for but others would get him? I imagine his travel speed would have no effect on the end result of running into that demon mouth trap in tomb of horrors after all.

If a player were to say "I want to run 300 feet back and forth triggering all traps in the halls/rooms/whatevers and escaping before they can effect me" to me, I would say "that is not how traps work. If you trigger them you get affected, a huge walking speed does not change that.


Its not so much the travel speed of the arrows as the time it takes from hitting the trigger to setting it off and said arrows being aimed at where a standard player would be standing. Think indiana jones and the rolling boulder temple he raided. In one section (https://youtu.be/mC1ikwQ5Zgc?t=105) he dodged the dart traps because he was sprinting full out to escape and who is crazy enough to SPRINT through a trap filled ruin?! No wonder they werent aimed right to nail him. This would be a more advanced version of that due to better traps, but also a guy running about 20x faster than indiana.

If this was a D&D game session, Indiana would have avoided the darts either because his AC was higher than their attack roll, or because he succeeded his save.

His speed is not a factor in the equation.



I just did a quick scan and it seems like dart traps and such are built along those lines, single trigger, single dart path. If a single trigger filled the entire room with darts that would be another matter. I agree that at least some magic traps, namely always on traps, like anyone entering a room is hit by a hold person spell automatically, or there is a mist in the room that forces an int save or you get feebleminded or whatever wouldnt be avoided by a full sprint, but again, trigger traps, unless they effect the whole room at once, just seem like they wouldnt have the chance to effect something moving that quickly.

To go back to the dart trap for a moment, this is what I got from a quick google for 5e traps. Basically, unless that dart reaches him in less than .1 seconds of him hitting the trigger, its going to miss. He is traveling about 100 feet per second. That was the main reason I called for a ruling. Mechanical triggers traps, unless they trigger something with a wide area of effect, shouldnt work on someone moving that fast. Pit traps would probably work though as thats the floor dropping out from under him all at once.


You can't alternate between game logic and real life logic to get the result that you want.

A character with 600ft of movement is not moving 100 ft per second, for starter, if you use game logic.

If you use real life logic, then going from 0 to 100ft in 1 second means your body is subjected to ~3 g of force. That's about what you get in a roller coaster, and it's definitively not something a human can handle with no debilitating effects.

[OldTrees1]

600ft per round is not that fast in D&D terms. The baseline is 60ft per round. A Rogue is 90ft per round. If they want to be a speedster, I would work with them on some homebrew feats / alternate features / etc to increase that speed.

However speed would be a factor for some traps.

For some traps there would be a speed threshold that gives you the effect of the Dodge action (disadvantage on attacks vs you, advantage on your Dex saves) and another threshold for negating the trap. For simplicities sake I would divide this into 3 speed thresholds with the PC starting above the 1st or 2nd threshold with room to grow beyond the others. Which traps fall in which categories depends on the PC's starting speed.

At 600 ft per round (so 7x as fast as the Rogue) I would say:
Falling brick? Negated
Swinging Pendulum? Negated
Pit trap? Advantage on the dex save and failure means tripping against the far edge rather than falling down the pit.
Long pit trap (say 20ft+)? Advantage on the dex save or fall in.
Arrow? Disadvantage on the attack.
Lightning Bolt? Reach 900ft per round and you can have advantage on the save


But other traps would not be affected by the speed. Either because they are instant, or because you ran literally through them (invisible wall, a persistent gas, etc)

Other traps would still be effective because they hit a large enough area (falling ceiling) or don't aim for you (walls blocking escape / activating golems).

Finally, some traps get more dangerous to a speedster. Those traps will only exist initially by accident because the speedster is a rare / unique / novel opponent. However a recurring BBEG might string up a decapitation wire. Personally if I were the DM I would not intentionally place any of these traps. If a trap accidentally has this property, then I would run with it. If the speedster PC causes the BBEG to make a tailored trap, then I would run with it. However by default these would be avoided. ... I just realized running into an invisible wall would count as one of these accidental more effective traps.

[False God]

Sure. They're spending time to protect the other party from danger, there's a slim chance of failure depending on the nature of the traps, and they're having fun doing so.

Better than 10'-pole-ing the room.

[Unoriginal]

The only type of traps where your speed is a factor is the "pursued by something that will hurt you if it reaches you" kind. Like Indiana Jones' rolling stone, or other unstoppable groups of rock.

EDIT:

Or to put it other terms: a character that moves 600ft during one turn is just as subject to regular Attacks of Opportunities by the enemies whose spaces the character leaves than anyone is. There is no reason why a character who can get hit by a Hill Giant's club can't be hit by a trap they triggered.

[Kemev]

As a dm, what would be your reaction to "I want to run 300 feet back and forth triggering all traps in the halls/rooms/whatevers and escaping before they can effect me" as a style of scouting...? <snip> Would there be some traps you would allow that for but others would get him? I imagine his travel speed would have no effect on the end result of running into that demon mouth trap in tomb of horrors after all.

When I'm DM'ing, I spend a lot of time trying to figure out what seems reasonable. I believe in saying "Yes, and..." as often as possible, but I also believe that restrictions breed creativity, so I don't necessarily want to greenlight everything the players want to do.

In this case, a player designed their character to be super-fast, and presumably their character absorbed some opportunity costs to do so (ie, they gave up damage, spellcasting, other class features, etc). Should they be able to use the character they designed to get an advantage on problem solving?

Yeah, that seems reasonable.

But could the character completely negate a large area of the dungeon? Well, as a DM I only have so much content to use for a game (I'm limited in either in terms of my time to design puzzles, or money to buy adventures). If I let a player walk through a large part of the session, it can limit the amount of game to play (which in turn limits me and the other players).

That doesn't seem reasonable.

So I want to give this player a chance to shine, but I don't want to give them a walk-over. And D&D already has a mechanic for this... advantage. In this case, I'd give the speedster advantage on saves vs. this set of traps (or disadvantage on the traps' attack rolls). Depending on the exact trap, I might also give Speedy resistance to any damage it deals.

Longer term, beyond this particular session, I might think about what's the player communicating to me with their play. What's going to be reasonable for future encounters? Are they (and the rest of the table) saying they don't really like traditional dungeon crawls? Do they want to literally zip by and get to a more fun part of the game? If that's the case, as the DM I know I should stop preparing trap-centered dungeon crawls. Or do they like this style of puzzle, and being speedy was a useful solution? If that's the case, I should get more creative and look at traps to thwart the Flash. (The decapitation wire is a good suggestion. Or maybe there's loose rubble, ball bearings, or Grease that the character gets disadvantage on... going too fast makes them at extra risk for falling.)

[JackPhoenix]

You can't alternate between game logic and real life logic to get the result that you want.

A character with 600ft of movement is not moving 100 ft per second, for starter, if you use game logic.

If you use real life logic, then going from 0 to 100ft in 1 second means your body is subjected to ~3 g of force. That's about what you get in a roller coaster, and it's definitively not something a human can handle with no debilitating effects.

It also means that once the character inevitably trips or slips on something, he's hitting a wall or other obstacle at about 100 km/h. That's rather fatal.

[Unoriginal]

It also means that once the character inevitably trips or slips on something, he's hitting a wall or other obstacle at about 100 km/h. That's rather fatal.

Well the simple fact of moving one's legs in a running motion at that speed would be enough to at least severely damage one's hips, knees and ankles, as well as most muscles involved in the movement.


In any case, I reiterate: you can't Guy at the Gym the various traps but not Guy at the Gym the runner. It's either both or neither.

[NorthernPhoenix]

I probably wouldn't let someone play a character like that in the first place. Some players may find that harsh, but i want to let you DMs out there reading know: It's OK to say No! You don't have to allow any maniac build someone has pulled off the internet if you don't want to.