D&D 5E Who arrives first? Can DMG chase rules be adapted to a race scenario?

[Quickleaf]

I have a scenario in a for-publication adventure I'm working on where the PCs may receive a sending of an imminent attack on some allied priestesses.

The question, as I'm framing the scenario, seems to be: Can the PCs arrive in time to stop the slaughter of the priestesses?

How would you handle this?

In the past, I've seen this done (and have done it) with DM fiat. But I'm wondering if there's a way that gives the players more involvement? So here's my options as I see it...

(1) Adapt the DMG chase rules somehow. Can this work? Has anyone done it? The goal is not to catch target X, but who reaches destination Y first.

(2) Design a 4e-like skill challenge or some other customized mini-game. A lot of work/page count for a "this might happen" scenario.

(3) DM fiat, with a bit more organization based on quest goals the PCs have accomplished up to that point. For example, say there are "points" they can accrue accomplishing various goals (e.g. setting up spies on the villain who ends up launching the attack), each "point" meaning they arrive in time to save a priestess, maybe some kind of "condition track" depending on how many points they have that determines how bad (or not) the slaughter is.

 

[Saeviomagy]

The DMG chase rules are 99% "who has the fastest movement rate" with a small amount of DM fiat thrown in. Just about the only bit of them that works without major modification is the limit on how many times you are allowed to dash before you have to make con checks to keep doing it, and the general idea of the random occurrences.

Personally I run it (somewhat) like this:

1. I mark down the starting positions of each participant in terms of distance.
2. The lead character (only) rolls for disruptions, which occur at some point along his movement. Their distance from the start is recorded, and each player encounters the same hazard (but potentially with changes from prior interactions).
3. Each character other than the leader can choose to take a 'short cut', generating an alternative path for his next round of movement. Shortcuts are faster or slower based on a d20 roll, plus each shortcut has another roll for disruptions. The distance of the shortcut from the start is recorded, and following characters can choose to take it as well.

I'd also recommend your point 3 - the players preparations matter.

 

[iserith]

I would create three obstacles to overcome on the way to saving the priestess. Overcome all three and you save her. Fail to overcome all three and she dies. If the PCs overcome 2 out of 3, they save her, but there's some kind of complication or cost.

 

[Lackhand]

How far away are they? Rounds, minutes, hours, days? Depending on the scale, you might just run the adventure with no special rules, it just has an overland component. The overland rules work, there's a bunch of 5 mile hexes between here and there, and you have exactly enough time to cover the space taking one short rest (or one long rest? Or do you press through the night? etc).
If you did this, wrinkles include unfamiliar terrain (so: You present a picture of a mountain range to the party and ask them to mark with a vertical line where in the mountains they bear for; one of the spaces between the peaks is a high but passable valley, the other is inhabited by spiders, and the third is a slow slog over ridged terrain), patrols of unfriendlies on the plains, or a friendly-but-lonely copper dragon who will delay the party but then happily ferry two or three of them ahead at a time (and the ones who are left get the opportunity to interrogate the dragon's magic mirror or something).

It doesn't sound like the party can have direct and current interaction with the villains, so if you're just trying to figure out how long the villain has, your #3 "goal point system" sounds like the best way to resolve it.

Are you assuming the party is traveling as a whole, and the villain is coming along some other path? If you are, then I might just present it as a little minigame choice: "You'll need to travel 6 miles. Traveling at a slow pace will take 3 hours, 3 random encounters, but you're at advantage to go unnoticed. Normal takes 2 hours, but you risk 2 random encounters. Faster takes 1.5 hours, but also takes 1d6 damage and a DC 10 con save or acquire 1 exhaustion AND you risk 2 random encounters with disadvantage to go unnoticed". And that's that. And if you prefer real encounters to random encounters, or have some other distance or whatever, that's fine too. (assuming slow was a real option, I'd probably take it given those odds!)
This version doesn't use a map -- "we follow the road to the temple, dagummit!" -- but stresses the timely nature of the journey. You can even somewhat stack the deck: "slow" won't cut it, because they have 2.5 hours before the bad guy shows up.

Are you prepared for what happens in the adventure if they miss the timing event?