Rolling for Movement in Theatre of the Mind

Question

From D&D 5e and "Theatre of the Mind" in combat, mxyzplk had the second highest answer about running combat in theatre of the mind. He mentioned:

Same thing with movement. I have all my players convert their movement into an actual "Move bonus", +2 per 5' of movement, so a 30' move is a +12, for example. (Side rant, the conception of movement as fixed when everything else in the system is a variable is one of the greatest missed opportunities in D&D design and all the other games that blindly inherit their metaphor from it.) "I want to get around that orc and flank him with Billy!" "OK, roll Move. You're not even inside the door yet and there's a bunch of other orcs, so I'll call that DC 20, fail means you get to melee but not in flank, fail by 5 means someone AoOs you on the way."

This got me thinking of how to implement this. I was unable to find any other posts or details that further explained this idea.

I'm imagining that the DM will set a DC that would have to be overcome to successfully move. Rough distance and/or enemies would cause an increase in that DC, things like disengage or dash would cause a decrease in that DC. However I don't have enough details to flesh out a homebrew rule that would be balanced and not cause more headache than it's worth.

Are there any existing systems similar to this that I may have missed or are there any good examples that can be provided to serve as a base for fleshing this out?

Answer 1

I'm going to assume we're restricting this to theater of the mind mode.

You can use the same rule with battlemats and such of course, in which case instead of DCs you just roll for how far you move exactly. I have a set of chase rules on my blog that use this approach, and I've used these extensively in campaigns for foot chases, horse chases, ship chases, and so on.

For theater of the mind mode, Spitemaster is correct: you don't roll unless it's interesting. If people just say "they move," you let them move, just as you don't make someone roll Athletics to jump over the curb. Use the general Passive rule; if the DC would be 10 + their bonus or less, don't worry about it.

You're using it when someone wants to do something that you as the DM think might take more than one move, or be dicey, but you can't "prove" it because there's no battlemat and the players feel like you're against them if you just say "no."

"Can I run around behind the bulette and flank with the fighter?" asks the dwarf? Hmm, that's a lot of move for a dwarf... Roll it. DC20, you don't make it you end up along its flank proportional to how bad you miss the roll. Roll a 1 and maybe it gets an attack on you.

"Can I catch the fleeing orc?" Maybe, maybe not... Roll it. Beat the orc's move as a DC yes, don't beat it no.

"Can I light the fuse on the bomb and run and jump in the ditch before it goes off?" Maybe, maybe not... Roll it. DC based on how reckless vs. planned I think you're being. If you set up the bomb, DC 20, if it was just lying there and you have no idea how long that fuse is, DC 27. Maybe if you get above 15 you get to save for half damage.

A Dash (or in older eds, a double move) has a non-deterministic effect. If you take your whole action to dash, well of course you can get around behind the bulette. To catch the orc, I'm assuming you were Dashing because he is too, if you aren't you probably don't even get the roll (unless your move is way higher than his to where it could be competitive). Same deal with the bomb, if the ditch is only 30 feet away why would you be rolling? I'm assuming it's a stretch. As usual for 5e, apply advantage or disadvantage for complicating factors (poor footing, having to Disengage first...)

Trying for too much precision is against the point of theater of the mind.

You DC based on how hard you reckon it is and come up with tradeoffs to give the PC interesting choices - the main complaint of being off the battlemat is not having tactical decisions to make. "DC 30 if you go way around the bulette, DC 20 if you're willing to risk an attack in its reach." Rulings, not rules is the heart of theater of the mind.

Answer 2

Your suggestion goes against the general philosophy "Only roll when it's interesting." You wouldn't make your players roll to walk across the street just because it's snowy - if they fall down, there are no consequences. In the same way, you don't want to make them roll unless:

• There is a chance of failure.
• There is a cost of failure.
• There is a chance of success.

Now, that's not to say that the bones of the idea aren't interesting. You could reduce regular movement (by 5 feet, maybe), and then have a DC for movement past that, with Dash giving you advantage and a +5 bonus. Here's a sketch of how that could work:

• Base movement converted to bonus: 20 -> +6, 25 -> +8, 30 -> +10, etc.
• Target distance DC is 15 + 1/3 of the distance (30 feet -> DC 25, 50 feet -> DC 31, 60 feet -> DC 35)
• DC increased by 1 per 5 feet of difficult terrain moved through.
• If the target DC is missed by 10 or less, the penalty is moving (3*difference) fewer feet.
• If the target DC is missed by 11 or more, the character falls down in a random space they tried to run through.

(These numbers should be workable, but I don't know whether they'd be good)

This would make moving around much more interesting, especially with ad-hoc rulings for how challenging a certain thing would be. But the most important thing is not to call for movement rolls every turn, or it would just become frustrating.

Oh, and in particular: It doesn't make sense to do this if it's in the Theatre of the Mind. You shouldn't be tracking distances exactly enough for it to be an issue in that case.