I played the final session of D&D Encounters (season one) last night. Overall, I think it was a good encounter, and I’ll probably be stealing some elements from it for future use.

The thing that this encounter really served to highlight was how important a factor terrain can be in a fight when the monsters and the environment are built to go together. The environment was a cave with a rushing, icy river running down the middle of it. There were two main ways across the river: jumping across (which would be difficult for those not trained in Athletics), and navigating a slippery bridge that required an Acrobatics check if you wanted to move more than two squares on your turn. Most of the monsters were on the far side of the river (and there were a few that seemed placed specifically to block the party from the BBEG), which meant that the river was always going to be a factor that you had to consider.

What made it even more interesting was that more than one of the creatures had abilities that capitalized on the environment in some way or another. In fact, all of them did. The choker and the spider could both crawl around on the ceiling, dropping on unsuspecting PCs and avoiding the river entirely. The archers were placed well, far away and with multiple obstacles between them and the PCs, forcing the PCs to endure their attacks for a while before they could close the gap. The BBEG had multiple abilities that pushed and pulled, and he used them to knock us all into the water as frequently as he possibly could.

What this really reminded me of is that, when you create an interesting environment, you want to select your monsters carefully to make sure they fight well in that environment. Similarly, if you have a bunch of monsters with similar abilities, the right environmental effect can make those abilities a lot more effective in combat. Pushes and pulls on their own are more a nuisance than a threat, but as soon as damaging terrain enters the equation–particularly if said damaging terrain is difficult to navigate around in the first place–those pushes and pulls become a true threat.

I feel that creating encounters such that your monsters and your environment harmonize without being too difficult or annoying is a subtle art, and one I have yet to master. I think I occasionally pull off some good combinations, but I think I have a lot to learn about how best to implement this kind of combat.

Related posts:

1. Encounter Roles
2. Planning for Spontaneity
3. Encouraging Terrain Powers
4. DM’s Journal: Creating an Encounter in 4th Edition
5. Tools for Encounter Design