Set piece encounters

[RavenStarver1]

In my game the players are currently two months travel from known civilization, as part of an expedition seeking to plunder an ancient dwarves Thaig. They're going to run afoul of a large group of orcs that currently live in the upper levels of the Thaig.
What I'm wondering is how should I go about the battle?

Setup: there are forty other people in the caravan, all of whom are at least of Guard level, the toughest is a Knight, and they have twenty wagons. There are 70-80 of these orcs, some on Wargs, some archers, mostly melee.

I'm wondering where would be a good location for the battle so it doesn't just happen in a flat, boring, featureless field. There are forests, fields, hills, stones and crags, the ruins of a dwarven town, etc.

[Jama7301]

I'd maybe set it up in the broken down town. There's something about a fight in a ghost town that's appealing, as people circle an empty well in the center of town, and archers taking pot-shots from windows. Could burst into an old saloon to try to get the archer on the rickety second level. Maybe a row of buildings got tore down and are now difficult terrain instead of being in the way.

[Tiadoppler]

Do you intend to use minis/tokens on a grid, or theater of the mind?

If it's theater of the mind, I'd suggest draawing a small scale map of the battle anyway, just to show where things are (a road through a narrow ravine, with ruined buildings carved into the cliffs on either side?).

Do you intend for this to be a mobile battle, or fairly stationary/defensive?

A battlegrid 5e encounter with 120+ individual units is marginal at best. It's not quite big enough for the UA mass combat rules and but way too much for a regular encounter. I've run 50 unit encounters before and it get's rough, even accepting that many units are mooks with identical stats whose combat effectiveness is averaged out rather than rolled individually.

[RavenStarver1]

Do you intend to use minis/tokens on a grid, or theater of the mind?

If it's theater of the mind, I'd suggest draawing a small scale map of the battle anyway, just to show where things are (a road through a narrow ravine, with ruined buildings carved into the cliffs on either side?).

Do you intend for this to be a mobile battle, or fairly stationary/defensive?

A battlegrid 5e encounter with 120+ individual units is marginal at best. It's not quite big enough for the UA mass combat rules and but way too much for a regular encounter. I've run 50 unit encounters before and it get's rough, even accepting that many units are mooks with identical stats whose combat effectiveness is averaged out rather than rolled individually.

We actually game on Roll20 so there will be "minis" that we'll be using. If the party tries to make it a mobile fight they're gonna have a really bad time. They're outnumbered two to one and ox-drawn wagons are not fast vehicles.

[Tiadoppler]

I don't know Roll20, so I can't help with that aspect.

Is there any way to focus on the PCs aspect of the battle, while the rest of the battle happens just offscreen? A pass or bridge that can be blocked and defended by a small group (PCs + a couple allies), a tunnel that needs to be cleared out before the caravan can proceed? D&D really works best with small combats (10-25 combatants IMO).

Do the orcs have a goal other than "kill the intruders"? Is there a reason for them to attack into fixed defenses instead of skirmishing and picking off the caravan members one by one?

[Joe the Rat]

I'm going to assume you have a plan for the mass NPCs to make it quick, or keep the players involved.

I'm wondering where would be a good location for the battle so it doesn't just happen in a flat, boring, featureless field. There are forests, fields, hills, stones and crags, the ruins of a dwarven town, etc.

Forests: Cover options, line of sight breaks can obscure off-camera activity. Not many hazards available.

Fields & Hills: with some exceptions, this is pretty close to featureless plain. If you could add a river, however...

Crags: Cover, high ground options, difficult and unstable terrain, fall damage. Lots of options here.

Abandoned town: cover in spades, obstacles, open or blocked roads, rife for ambushes and traps. Fortified buildings as mini castles.

Town or rocky crags give you the richest options