Encounter Locations

Features on the map have a substantial impact on the flow of combat. Three considerations to keep in mind when designing a map are maneuverability, line of sight, and attack ranges. Even empty rooms and corridors can provide variety based on their size and shape. Narrow passageways make natural choke points. In particularly small rooms, space is at a premium, favoring melee combatants and making area effects hard to aim without friendly fire. By contrast, huge areas lend themselves to spread-out combat, which gives plenty of room to use all manner of abilities but poses challenges for ones with limited range. To make large rooms more interesting, add furniture, columns, or other features the PCs and their foes can duck behind for cover. Also consider how far away combatants start from their cover, as spending multiple actions to reach cover can make it a far less attractive option.

In most cases, the PCs enter territory that's far more familiar to their foes than it is to them. NPCs and monsters who live in an area are likely to be adapted to its dangers, either because they know where they are and how to avoid them or because they're unaffected by them. A CEO in his penthouse might bait a PC into walking into a trap programmed to attack intruders. Marshland might be troublesome terrain for most PCs, but it poses little inconvenience to amphibious creatures. When using creatures with the ability to burrow, climb, or swim, consider incorporating features such as mazelike corridors, high walls with platforms, or rivers. If the foes are smaller or larger than the PCs, consider including paths, vents, staircases, or narrow passages that one side of the fight can use more effectively.

Sometimes, though, the PCs must defend their own base from intruders. In these situations, you're flipping the script, so give the PCs time to trap and ward the area. Watching the invaders fall prey to hazards and ambushes can be a delightful change of pace for your players.

On a clear, sunny day, the PCs see clearly and fight without obstruction, but adding wind, precipitation, or fog creates additional challenges. Rain creates sloshy, muddy ground that slows movement, and cold weather introduces the threat of slippery patches of ice. Only the most extreme temperatures have a direct impact on the PCs during an encounter, but a slog through blistering heat or freezing cold can leave the PCs worn out and more vulnerable to foes. Light levels play a key role in both outdoor and indoor encounters. Although flashlights are plentiful, their reach is limited, and lights are sure to draw attention in dark places.

The hidden infrastructure of a typical building or spaceship likely contains numerous mechanical, electronic, and plumbing features concealed in walls, ceilings, and floors that are unlikely to be a part of even the most comprehensive map or room description. While modern infrastructure can usually be ignored, a crafty or panicking player might choose to attempt to make use of both the described and inferred features of a constructed environment. You should always feel comfortable explaining to a PC before they waste actions that their character doesn't think the idea is possible given the limited amount of time and resources available during an encounter.

If you're up to the challenge of adjudicating these features on the fly, you can find similar environmental effects and guidelines for environmental damage. It should probably take an entire round (or more) to complete the setup, which can give you some time to consider an appropriate reward for a PC's efforts. For example, if a PC wants to find a live power line to shock a robot, you might require a Crafting or Engineering Lore check to determine where they can find a line in the wall, an Athletics check to Force Open a panel in the wall, and an Interact action to grab the wires safely enough for the PC to Strike with them next round. Knowing it will take 4 actions with a chance of failure is usually enough to dissuade a PC from attempting that sequence of actions, but the rewards can make for a memorable story!

If you include terrain that's tricky to navigate or takes extra work to deal with, consider whether it should count toward the encounter's XP budget. A fight that requires Climbing, Swimming, Flying, or pushing through difficult terrain can be tougher— especially if the enemies have protection from ranged attacks. Think about the impact of the terrain in advance, especially if the battle would already be a severe threat, or you might kill the party. Consider the effects and ease of finding cover as well as the maximum range of the weapons being used by all combatants. You can pick an equivalent monster level for your terrain and factor that into your budget, or just assign extra XP at the end if the threat without terrain is on the low or moderate end.