The Terrain Is An Adversary
Header Art: Gamemastery Guide (2020) by Paizo Inc.
There are more adversaries in a battle than just the monsters you have carefully selected to rip your player’s characters apart. The way you draw a room, how close or far you place the monsters, how far apart the monsters are from one another, and, one of the biggest, the general terrain of the environment.
Terrain is a major adversary in an encounter, though it is often forgotten about or pushed to a corner. Even the Dungeon Master’s Guide (2014) only offers two sentences about how terrain can help contribute to a fun combat encounter with only the barest of examples. In truth, terrain should be a much bigger consideration when it comes to building encounters. You wouldn’t put a monster like a shadow in a brightly lit room, just like you shouldn’t put an archer in a non-descript room with no elevation, cover, or difficult terrain.
Types of Terrain
Just as there are different biomes, character classes, monsters, and more; there are different terrain types that you can populate an encounter or battlefield with. Each type is going to have its own way of interacting with the encounter and could be beneficial for some characters and monsters, and harmful for others. There are five main types of terrain: Difficult, Distance, Cover, Sight, and Skill. In addition, these terrain types can be combined to create even more types.
It’s important to remember that if you do the same thing over and over, that does not make an encounter interesting or fun. In addition, diversity brings greater fun, but only to a certain point. If you throw every terrain type into an encounter, it can be a crazy and confusing mess that is more trouble than it’s worth. Use different types of terrain, but be conservative with how much you use.
You want just enough to create meaningful choices and provide interesting tactical choices to the players. Too much of anything is a bad thing.
Difficult Terrain
Probably the type of terrain most people are familiar with, difficult terrain requires extra movement for a creature to expend to go a set distance. Most difficult terrain requires two feet of movement for every one foot move, i.e. it takes ten feet of your movement to move five feet, but that isn’t the extent of difficult terrain.
You can have varying degrees of difficulty, even within the same encounter. A swamp can get deeper, meaning that along the shoreline it takes two feet per foot of movement, but the deeper you go in the sucking muck, the more that is required. Why you might decide to have a variable amount of difficult terrain is because it can turn a small encounter area into a larger one and require the party to expend precious resources, like spell slots on fly or teleport spells. By creating variable difficult terrain, you can have a single passage that is more winding throughout the encounter, allowing a soldier or brute to better protect their ranged allies unless the party is willing to wade through thick mud for a more direct line of attack.
In addition, difficult terrain can be more than just slower to move through areas. It can also include areas that are blocked off, like from a collapsed ceiling, that has just enough space for a spellcaster or artillery monster to fire missiles through without getting hurt by melee creatures. The following are a few ideas to include in an encounter.
Rubble has fallen from the ceiling, making it slower going for creatures to move across the open ground and reach the ranged combatants on the other side.
Deep sand provides a more direct line towards the enemy, but it requires more movement to be expended, which could be slower for low-speed creatures, like small-sized creatures who can only move two squares per movement (25 feet / 2 = 12 feet, rounded down to 10 feet) or be a more viable option for high-speed creatures, like monks.
Avoid using too much difficult terrain in areas where you want combatants to fight in melee. An area void of difficult terrain will encourage them to move in that area and fight there, allowing you to plan for other effects to happen there.
Fallen trees in a forest can provide sporadic and natural difficult terrain, giving your player’s characters an opportunity to jump over the trees (if their Strength is high enough) and avoid the difficult terrain, spend the extra movement to go over the fallen tree, or go around if they so wish.
Steep slopes can be not only difficult terrain, but chances to allow creatures to move faster downhill. You could consider giving creatures a faster speed when running down a steep slope, while requiring extra movement to be spent to run up a steep slope. This can be advantageous for a group of monsters to run down at the players, while it will take the players longer to run up the slope towards the ranged combatants in the back.
Pools of deep water can allow a creature with a good swim speed to quickly move and outflank the party, while the party is forced to either swim or wade through water, slowing them down. This is especially helpful for monsters that like to move in, strike, and then move out quickly.
Difficult terrain can also be ‘impassable’ terrain, like wide chasms, collapsed roofs, and more. This impassable terrain allows you to steer the combatants into specific locations while allowing creatures with unique abilities, like earth glide, and those with powerful spells to ‘cheat’ or negate the obstacle placed there.
Distance Terrain
As the name might suggest, this is all about how far away you set the encounter up, and where each monster is along that distance. While the party might start near a brute or soldier monster, that doesn’t mean that every monster has to start next to the party. You can spread multiple monsters out across various distances, like melee combatants close to the party, spellcasters a full movement away, and artillery combatants even further than that.
When using distance as a terrain feature, think about the following:
Small rooms make it harder to use larger Area of Effect spells without hitting your allies.
Large rooms allow ranged combatants to be further from melee attackers.
Small rooms keep a battle static and in one area.
Large rooms allow defenders in the back to escape easier when their front line is beaten.
Small or narrow rooms or passages make it easier for fewer monsters to control an area and keep other creatures from getting past them.
Large rooms allow bigger creatures to move easier.
Small creatures are going to build small hallways, forcing creatures that are bigger than them to squeeze through to get to main chambers.
Cover Terrain
Cover provides defensive positions, AC bonuses, and safe locations for ranged attackers. Anytime you put down a column, a bush, or another object, you are making an area that is harder on ranged attacks and makes sneaking around easier. Monsters can set up an ambush in a set of ruins or archers can be set up on a ledge that they move back and forth on, hiding away after they make their shots.
Cover allows you to break up an encounter area and has some synergy with difficult terrain. You can create areas of impassable terrain, but with openings and slots for ranged combatants to fire through and be fired upon, but with a bonus to their AC. A few examples of using cover are below.
The city or castle walls have merlons, a small protrusion at the top of the wall, that provides cover from outside ranged attacks and allows creatures to hunker against.
Fallen timbers have provided archers and spellcasters a safe nest to fire missiles from. Since the timbers are at least five feet across, any melee combatants must crawl over them to reach the ranged combatants.
Cover for melee combatants allows them to move from one area to the next, avoiding the attacks of ranged combatants firing at them from a defensive position.
Too much cover can make it hard, or almost impossible, for a ranged combatant to make any attack. Instead, cover should be used to force creatures to move about the encounter area and find tactical locations where they can overcome the challenge of cover.
An open doorway can provide cover, with a ranged combatant coming out from behind the door frame, firing a missile, and then ducking back behind the door way. This can be especially troubling for a party blocked by a brute or soldier who is clogging a hallway, not allowing the party to get past them and deal with the ranged combatant.
Sight Terrain
Sight terrain is the visual aspect of cover, but relies on breaking up line of effect, making it hard to find your enemies, and reducing the impact of spells. Often sight terrain comes about from spells, but could be produced by campfire smoke, a low fog that hugs the ground, a heavy rain or snow storm, or some magical effect that has come from another world. You can even use bushes, corn fields, and other natural elements that aren’t difficult to move through, but are thick enough to block sight. A few examples are provided.
A cornfield means that small or tiny creatures can easily disappear into the field and not be seen until they strike.
Thick tree foliage means that combatants on the ground can’t see flying combatants above them, making it so that they can’t make their attacks until they see them.
Magical darkness is cast on an area where ranged combatants are, making it so that they have to move closer to melee and removing their high ground, cover, or distance.
Low fog has been magically summoned in the area, meaning that fighting only occurs at short range, making it hard for ranged combatants to be effective and that melee combatants must hunt through the thick fog to find their enemies.
Stealth focused characters and high speed strikers excel in the low visibility, allowing them to hide within the low sight lines or to escape into the fog, forcing other creatures to follow after them into traps.
Spellcasters are unable to target creatures from afar with spells that require them to see the target, limiting what spells they can use.
Dungeon Master’s Guide, 2008 Wizards of the Coast / Eva Widermann
Skill Terrain
While there are many obstacles to overcome in an encounter, some require those who are highly skilled to properly overcome them. A massive log is an impassable log unless someone can climb over it with athletics, a thicket of thorned brambles could require a survival check to navigate or take damage, while a narrow log bridge, perfect for small creatures, requires a larger creature to balance across with acrobatics.
By requiring a skill check to pass through an obstacle, you can create sections in the encounter that are harder to overcome and, depending on the dice, might require more than one attempt. This slows down creatures, giving ranged creatures a chance to get another volley in or for melee creatures to catch up and force their enemies into combat.
A slick ice sheet requires creatures to keep their balance with Acrobatics or fall prone - or take the long way around.
A broken column leans to one size, allowing access to the ledge overhead - but it will require a creature to either climb with athletics or run along the top and keep their balance with acrobatics.
A rough sea tosses those swimming around, requiring them to make athletic checks to swim or be plunged dozens of feet underwater.
A thick hedge of brambles has a few good locations, but requires a creature to make a nature or survival check to know where to step or take damage from the thorns. This can be applied to a thin ice sheet, with failure resulting in the creature falling underwater and being trapped beneath the sheet of ice.
Traps are hidden throughout the room, requiring a creature with a good perception or investigation check to know where they are. If the traps are magical or unholy/holy in nature, you could then use arcana or religion to avoid them.
A dangerous animal’s home is nearby and it will require an animal handling to ensure that the animal doesn’t attack the party, but their enemies.
A wide ravine or chasm splits the room, forcing creatures to leap across and make it to the other side. A creature with a high enough Strength score can easily make it across, but others will have to make an athletics check to make it or fall.
Dungeon Master’s Guide, 2008 Wizards of the Coast / Brian Hagan
Terrain Roles
Just like a monster, the terrain should have a role in an encounter. If you are just plopping in difficult terrain to ‘spice up’ combat, then you are wasting its potential and it’ll probably end up being either useless or exceedingly frustrating. I’ve talked before about monster roles in an encounter, but a monster can only effectively use their role if they are placed smartly within the terrain. As a reminder, the different monster roles are Artillery, Brute, Controller, Leader, Lurker, Skirmisher, Soldier, and Spellcaster.
Artillery
Artillery shines the most when they can attack from range. Their melee damage is often pitiful compared to their range damage and their hit points are lacking. They rely on cover and distance to keep them alive, while destroying their enemies from afar.
Ranged combatants need to start out far from the players, though not every room is 100 feet long. Instead, artillery can rely on difficult terrain, hiding up on ledges, or behind cover to help give them that distance. They could have climbed up a column within the ruins of an old temple, hiding amongst bushes and trees, or be on the other side of a great hall behind a meatshield of their allies.
Brute
A brute is a massive slab of hit points. They are going to find themselves in melee, whether the party wants that or not, and they are often protecting squisher allies behind them.
Brutes need terrain that allows them to funnel enemies towards them. When designing terrain, players should have limited choices when it comes to get past them. To be effective, there shouldn’t just be empty spaces left to either side of the brutes, but rather restrictive terrain that will lead the party to fight brutes head-on in melee. If you allow too many ways to simply bypass the brute and attack its allies behind them, then the key role of a brute as a damage soaker is not used to its full potential.
Controller
In charge of controlling the position of creatures in an encounter, controllers might be the ones responsible for creating difficult terrain and other obstacles. They are often near the front lines, so they can utilize spells and effects that are long range, while doing their best to funnel creatures to their brutes and soldiers.
Controllers will often be those who create terrain, but also use the terrain to suite their purpose. If there is only a narrow hallway available, they can create an area of difficult terrain, slowing down melee combatants from reaching them. They might also create areas of magical darkness on the enemies’ range combatants, forcing them to move closer to melee or leave an advantageous position.
Dungeon Master’s Guide, 2008 Wizards of the Coast / Lee Moyer
Leader
In charge of all allies in an encounter, they are found near the front line, if not in it. They don’t deal as much damage as their allies, but they provide assistance to help their allies succeed.
Leaders are going to approach terrain differently based on what terrain is available. They’ll often, narratively, stand on top somewhere high so they can see what is happening, but close enough to their allies to offer aid. They might stay behind cover while offering boons to their allies, making them harder to hit, or they could be creating cover, stopping ranged combatants from hitting them or their allies.
Lurker
Sticking to areas of darkness or behind cover, lurkers deal big bursts of damage but it requires perfect conditions. They often require the most setup of any creature, with their base damage being quite low but if they can use the terrain smartly, they can deal a massive burst of damage that will immediately make them a threat to all.
They need areas that they can hide behind, darkness to hide their movements, areas of shadow, and more. Often they’ll have an ability that allows them to escape from attackers, but they need terrain throughout the room so that their prey can’t escape them or draw them out into the light.
Skirmisher
Known for going in and out of the front lines, skirmishers focus on having high movement. They don’t have good defenses, so on their turn they’ll jump to the front lines, or past it, deal their damage, and then run back to safety.
Skirmishers need terrain that will slow down their enemies without affecting them as much. They might have an ability that allows them to ignore difficult terrain, like having a swimming speed in the water or a fly speed so they can avoid mud. Or they could have an ability that allows them to teleport away once they attack, allowing them to escape from harm and forcing their enemies to chase after them. Impassable cover can be a boon if they have a way to pass through it but their enemies can’t follow them, like if they are a ghost passing through a wall.
Soldier
Defensive and powerful, a soldier is going to be on the front lines and in melee. They often have special abilities that stops creatures from simply running past them, but their reach is limited.
Soldiers will excel where there are certain corridors of movement that creatures are forced to follow. If a soldier is blocking a hallway, they can protect their ranged allies behind them and tank attacks with their high AC. Soldiers will falter, though, when placed in areas of huge, empty spaces. Their defensive ability won’t mean anything if ranged combatants can pick them off and the soldiers can’t reach them.
Dungeon Master’s Guide, 2008 Wizards of the Coast / William O’Connor
Spellcaster
Spellcasters have a varied role as they have a wide arsenal of spells and effects they could have. They are often merged with another role, so they will often require the same terrain as what they are merged with.
Ranged blasters will want cover and large distances to keep them safe, controller spellcasters will want to be near the front but require chokepoints to make sure they don’t get surrounded, but all spellcasters will require some elevated area that makes it hard to reach them. They don’t have the defenses needed to handle the front line and so they will seek defensive areas where they can avoid direct violence.
Building Encounters with Terrain
The terrain in an encounter is just as important as the monsters in it. If you build an encounter with creatures who like to hide in the shadows, but they are in the middle of a prairie at noon with no clouds, they are not going to be able to hide from their enemies and they will quickly be put down. By thinking not just about what monsters will be in an encounter, but how the terrain favors the monsters, obstacles that the party will have to overcome, you can create even more exciting encounters.
With that said, throwing in every element within this post will create a confusing slog. It’s important to carefully select what type of terrain best mixes with the monsters you are using and how to properly challenge your players. But don’t over do it. Constantly creating huge areas of difficult terrain is just as likely to make an encounter boring rather than exciting when the fighter spends a second or third turn just dashing across the area.
What type of terrain do you like using in your games? Was there an encounter you had where terrain created a more exciting battle? Share your stories below!
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