How to map out and run an encounter set in a predominantly vertical area online?

Question

Upcoming in one of my D&D 5E games, the player characters are going to have to venture down a dwarven mineshaft while being attacked by dwarf zombies. The shaft itself is an entirely vertical pit, with layers of stairs and scaffolding around the edge creating a path to the bottom.

I've researched into ways to do this, including this question here, and I would be happy to attempt to build a 3D model of the terrain, however the issue is that the game is entirely online. Usually for maps, we've used Roll20 which offers a nice top-down 2D perspective, and I can get some limited 3D out of it by placing things in layers. However, this method is already clunky, and with how tall the shaft is going to be... it's just really not gonna work.

So that leads me to my question, what are some ways I can represent this vertical area and it's associated encounter in an online-friendly way?

Answer 1

Use isometric projection map, for example:

Roll20 has a wiki page on how to use them: https://wiki.roll20.net/Isometric_Maps_in_Roll20

But if you're willing to use alternative applications, there are purpose-built apps for isometric-map building and playing such as Dungeon Builder

Also see this related question about mapping a vertical-heavy dungeon, though unlike your question, it doesn't focus on online playability.

Answer 2

Use a side view map

Something like this. If you really want to have interesting stuff on all four sides of the shaft, have four adjacent rooms/maps that turn the corner at the edges. If the shaft is small enough to where people might be jumping across or shooting ranged weapons or something, just note down the distance across and use that when judging whether people can target or move to spaces of similar height on the other 3 pages.

I've done muliti-page battle maps for Z-levels in primarily horizontal dungeons with significant vertical elements for a particular room before. It slows things down significantly on Roll20 as compared to real-life because moving tokens large distances is really annoying due to the tabletops problematic interaction with scrollbars. It also took a couple minutes for the slower players to learn how the maps related to each other. Nevertheless, it worked out fine-- the decrease in speed wasn't crippling and the ability to make use of the additional spacial relations in the room was exciting for some of the players.

I've used side-view dungeons before. They work fine and are immediately obvious even to most very-slow-to-learn players, though I imagine that would be different if you were playing with someone who had great difficulty learning new ways of doing things and had a lot of experience with top-down battlemaps. They are appropriate for primarily vertical spaces, and benefit from a sort-of genre convention that one of the two horizontal axes not be particularly interesting in combat nor difficult to map without representation, sort of like Z-levels in conventional dungeons.