The party, after a hard-fought battle through the troll encampment, tried to escape the driving wind by ducking into a nearby canyon. As they rounded the corner into the eastern mouth of the canyon, they found something they had not expected. The canyon floor was lined with bones of every shape and size.
Like the stones on the rocky shores of the Felsig Coast, thousands of bones lay strewn from wall to wall as far as the eye could see. It was impossible to discern what had taken place in this canyon, but their path was obvious.
They had come across difficult terrain before but making their way through this ravine was not only going to be physically difficult, but it was going to be mentally taxing as well.
What is Difficult Terrain 5e?
On the surface, difficult terrain might seem pretty straightforward. Quite simply, it is something hindering the path before the character. Anything can be put before the characters: from a seemingly impassable patch of ice to an unmanageable elevation, to the aforementioned piles of bones.
How you use it as a Dungeon Master or how you deal with it as a player, is what makes it more than just your boring bump in the road. Difficult terrain can change the game for the party by making movement more than just a walk in the park.
Free Movement
Before we get bogged down in terrain and difficulties therein, we need to talk about movement. The average player character movement is about thirty feet per round. There are many ways to increase that. A wood elf gets thirty-five feet per round. If they are a higher level Monk they can add an extra twenty-five feet. If they were to multiclass as a Bladesinger Wizard, they can add an extra ten feet per round.
Use of the Mobile feat combined with Longstrider, Zephyr Strike, and Haste spells can bring you up to 240 feet per round. Adding another 240 for Dash and bonus action dash makes that 720 feet per round. There are some other tricks that can give you even more movement, but this is pretty fast.
To give some perspective: A round is six seconds long, so that is about 120 feet per second. Usain Bolt, the Jamaican sprinter, runs about thirty-three feet per second when running a one-hundred-meter race. So, four times faster than the fastest man alive… as I said, pretty fast.
Normal Terrain
Movement speeds are based on normal terrain. A grassy knoll or paved street would likely pass as “normal”. As with most things in Dungeons & Dragons, what passes as normal is up to the Dungeon Master.
Your Dungeon Master might decree that tall grass is considered difficult terrain while mine may set the bar a little higher with a field of thorny brambles. Normal terrain, at the DM’s discretion, is anything that can be traveled using the character’s movement speed.
Terrain’s Difficult Past
The original versions of Dungeons & Dragons made dealing with terrain far more difficult. When the surface that needed traversed was anything other than paved stone or hardened earth the Dungeon Master had a map defining the range of the surface.
Swamps and mountains cost three movements per hex, crossing rivers also costs three movements, and woods or deserts cost two movements. This drew from war games, where players would move armies across continents and their varying terrains.
The “White Box” version of Dungeons & Dragons implemented terrain penalties. All terrain penalties are as stated in OUTDOOR SURVIVAL, mountains, and swamps cost three movement per hex, crossing rivers at non-ford hexes also costs three, and woods or deserts cost two. Tracks through mountainous terrain cost two factors per hex moved, and tracks through woods or swamps incur no movement penalty.
When TSR released the first Basic Set there was no mention of difficult terrain. Movement was simply based on the creature or character doing the moving. With the release of the Expert Set, adventurers were introduced to outdoor travel and thus, terrain.
- On a good road – 3/2 Normal
- Clear, city, trail, grasslands – Normal
- Forest, hills, desert, broken – 2/3 Normal
- Mountain, jungle, swamp – 1/2 Normal
A party can move through several types of terrain as long as it has enough movement to do so. All movement should be rounded to the nearest mile. For example, an encumbered party with a daily move of 12 miles starts in clear terrain.
They move 3 miles to a road (cost: 3 miles), travel 9 miles on the road (cost: 6 miles) and move 1 1⁄2 miles into the mountains (cost: 3 miles) before camping for the night (total cost: 3 + 6 + 3 = 12 miles).
~From Page 41 of the Expert Set rulebook
Terrain Today
In Dungeons and Dragons 5e terrain is greatly simplified. There are no complicated maps detailing movement across the landscape; there is no multiplication of inverse fractions to find out your travel speed. Terrain has been boiled down to whether the terrain is difficult or not difficult.
If the terrain is considered difficult, it costs you two feet of your movement for every foot moved. Basically, difficult terrain is one-half speed. If you typically have a movement of thirty feet, then your movement over difficult terrain is fifteen feet. Simple.
Combat rarely takes place in bare rooms or on featureless plains. Boulder-strewn caverns, briar-choked forests, treacherous staircases — the setting of a typical fight contains difficult terrain. Every foot of movement in difficult terrain costs 1 extra foot. This rule is true even if multiple things in a space count as difficult terrain.
Low furniture, rubble, undergrowth, steep stairs, snow, and shallow bogs are examples of difficult terrain. The space of another creature, whether hostile or not, also counts as difficult terrain.
~ From Chapter Nine of the Player’s Handbook
Doubly Difficult
While walking through a briar patch is considered difficult terrain and walking across a frozen pond is also difficult terrain, walking across a frozen pond that is covered in thorny brambles is not “double difficult terrain”.
The difficult terrain labels do not stack, so, although it may seem more difficult to walk up broken stairs that are made of ice versus steps of stone, either the terrain is difficult or it is not difficult. Imagine if you had broken, grease-covered steps, underwater that were overrun with thorny vines. Now that would be difficult terrain (but still only half movement).
Magically Generated Difficulties
In addition to naturally difficult terrain, there are several spells that induce this condition. One might ask why you would want difficult terrain as a player… but a carefully cast spell can slow the progression of an enemy, allowing the party to escape or at least better prepare for an incoming attack.
Although there are some spells that cause damage while creating difficult terrain, intentionally creating difficult terrain is an effective way to control the battlefield. Spells like Entangle can slow a group of attackers, allowing the party to pummel the foe with ranged attacks.
In 1415, during the Hundred Years’ War, the Battle of Agincourt was a victory for the English because the English forces knew how to use the terrain to their advantage. Because of a chokepoint created by the adjacent forest, the French army was forced to make their way through a muddy field caused by the recent heavy rains. The rains, combined with the recently plowed earth, made the field almost impassable.
When the French army was knee-deep in mud, Welsh longbowmen unleashed barrage after barrage of arrows. The French were unable to move as the arrows rained down upon them. Although the French won the war in the end, this was a turning point for the English army and most thought it would cost the French the war.
This tactical move was an effective use of the natural terrain, but you can probably see how, with a bit of planning, you could use this tactic on your battlefield. With the proper use of an entangle spell and a few crossbow bolts, your party can, at the very least, get a few shots off before the enemy gets themselves free to attack.
Spells to Use
Spells like Entangle and Grease will slow down an attacker on a smaller scale. If you need to cover a larger space, and you have the power, Mirage Arcane is a 7th-level spell that can make difficult terrain for one square mile for ten days.
You can also create difficult terrain indirectly by using spells like Speak with Plants or Move Earth to manipulate the existing terrain. Whether you are casting entangle or pleading with the local flora to block the path, these spells are cast specifically to make passage difficult.
There are a few spells designed to do real damage of their own but have a residual effect on the terrain. That list includes spells such as Spike Growth, Cloud of Daggers, or Ice Storm. These spells are a little less subtle than the previously mentioned spells. These spells have teeth and once the damage is dealt, the target must deal with getting out of the area without taking additional damage while moving at half speed due to difficult terrain.
Whether because of damage-dealing spells or the more subdued spells, it is important to remember that the movement of your party is also affected by this troublesome terrain. If your Wizard casts Grease on the hallway up ahead of you, you will have limited movement as you pass as well. You should probably make your way through the hall before making it impassable, or you might get caught in your own trap. This seems obvious now, but wait until you are in the heat of the battle, and you have forgotten how wide the area of effect of your spell is.
Avoiding the Obvious
Difficulties with terrain are inevitable. Either because of natural causes or because of caster-inflicted labors, difficult terrains are part of Dungeons & Dragons. Difficult terrain is about as unavoidable as an early-level goblin attack. Knowing how to avoid the agony can be incredibly helpful.
The obvious solution is avoiding the area. Walking around the giant glob of bubblegum is something we learned at an early age. This solution will only work in a few circumstances; you may not have time to walk around a mile-wide patch of ice or have the strength to jump a ten-foot puddle of grease in front of a door.
As with most problems in Dungeons & Dragons, there are spells to counter it. Freedom of Movement is the best example. Amongst other things, the target of the Freedom of Movement spell is unaffected by difficult terrain for one hour. Some spells, such as Fly or Levitate, simply help you avoid the terrain in question by moving around, or over, the hazard.
Other spells, such as Expeditious Retreat or Haste can help you increase your speed as to negate the movement penalty. Most of those spells have an hour duration and require concentration. If you are not a magic user or spell casting is not an option for you, there are magic items that can solve your problem. Medal of the Wetland and Ring of Red Fury, both from Critical Role: Call of the Netherdeep, make you immune to difficult terrain for a period of time. The Ring of Free Movement is akin to having a Freedom of Movement spell continuously cast on yourself.
Mastering Terrain
As a player, you will most often want to do your best to avoid difficult terrain; no one wants to move at half movement. On the other hand, as Dungeon Master you can really make a dungeon grueling with few well-designed landscapes. I am a big fan of using less obvious choices that will make the characters wonder why. Nothing induces cautious movement like a hallway filled with piles of arrows or a cathedral floor covered with ten inches of blood-soaked earth.
If the campaign is set in a marsh, then swampy muck might be the way to go. If your adventure takes place on Rock Candy Mountain, then I might recommend lemon drops and gum drops. Oh, what terrain that would be.
Creatures as Difficult Terrain
Another party member may be the last thing you would consider difficult terrain but moving through another creature’s space, friend or foe, is also considered difficult terrain.
You can move through a non-hostile creature’s space. In contrast, you can move through a hostile creature’s space only if the creature is at least two sizes larger or smaller than you.
Remember that another creature’s space is difficult terrain for you. Whether a creature is a friend or an enemy, you can’t willingly end your move in its space. If you leave a hostile creature’s reach during your move, you provoke an opportunity attack, as explained later in the section.
~ Player’s Handbook Chapter 9 – Combat
We’ve all been at a crowded store on Black Friday and the crowds are pushing through those double doors. Movement is unquestionably difficult. Half movement seems generous in most cases. A goblin hoard coming at you is no different. You cannot move through another creature’s space without difficulty.
Difficult Terrain 5e FAQs
As with all questions about the rules in Dungeons & Dragons, the true answer is up to the Dungeon Master. Nearly every rule book in 5e reminds us that the rules as written (RAW) are a guide and it is encouraged that they be broken to fit the table. The Dungeon Master is the master of the rules (with a bit of guidance from the sourcebooks).
Does Difficult Terrain Stack?
Difficult Terrain does not stack. No matter how many obstacles litter the path, movement is still reduced by half.
How does Haste affect Difficult Terrain?
If you cast Haste, after you are already in Difficult Terrain, you would treat your movement as Normal because Haste doubles your movement speed.
Do spells that cause Difficult Terrain affect friends of the caster?
Difficult Terrain applies to every creature in the area. The only exception might be if the creature secretes a slimy ooze that causes the area to be Difficult Terrain, the creature would likely be unaffected but when it comes to spells, yes.
The End of the Road
As the party climbed to the top of the last skeleton, a giant mammoth, at the western mouth of the canyon, they looked back over the path they had just traversed. They found they had a new respect for those explorers and adventurers who had gone before them and cleared the paths they travel.
