Difficult terrain 5e does not stack in D&D
Each foot of movement in difficult terrain costs one extra foot. That rule is valid even if multiple things in a space count as difficult terrain in 5e. An area is a d&d difficult terrain 5e, or it is not. But no area is more difficult terrain by becoming stacking difficult terrain effects in it. Regardless of the number of effects creating difficult terrain in one area, a consequence costs one additional foot per foot of moment. Sometimes the floor appears to be a unique case of difficult terrain that costs more, move to get through.
The water in the center area of the floor is two ft deep. The floor is very slippery-moving over this 5e difficult terrain costs 3 feet of speed for every single foot traveled. That is a case where the explicit overrules the general (the PHB difficult terrain 5e rules) and enables difficult terrain to cost 3 feet of the moment per 1 foot moved. However, that does not overrule the fact that difficult terrain still does not stack in d&d. Therefore, the challenge of walking through another creature’s place may not add to the movement fine.
Though not explicitly declared in the rules, it resembles the most relevant to choose the greater effect (the slippery floor) over, the lesser one (moving into occupied space). Not only is the floor impact greater in measurement, but it is also strong and affecting the entire area. The fine for moving through another creature’s space is restricted and conditional.
How do Big Creatures move through 5e Difficult Terrain?
Rubble, underbrush, shallow bogs, steep stairs, and other impediments are 5e difficult terrain that hampers movement of giant creatures in d&d.
Costs 1 Extra Square: Every square of difficult terrain you penetrate costs one extra square of movement. You do not acquire additional movement costs for devising a square of difficult terrain.
Large, Huge, and Enormous Creatures: Suppose such a creature enters two or more squares with varying types of terrain. You may count that square of movement according to the most difficult terrain. Count only squares it is joining for the first time, not squares it already occupies.
Ending Movement: Suppose you don’t have enough movement to enter a square of 5e difficult terrain. You can’t join it.
Flying: Monsters are not hampered by difficult terrain when flying.
Terrain Walk: Some creatures have a unique ability to ignore difficult terrain in special kinds of environments. For example, dryads have forest walks that allow them to ignore difficult terrain in forests.
Because every time difficult terrain costs one extra square of movement to enter, you may not normally shift into a square of difficult terrain. On the contrary, suppose a power allows you to move two or more. You can transform into a square of difficult terrain.
5e mold earth does it mean a soft spot is difficult terrain
Is it possible they only move two spaces in rugged terrain than, say, the bigger races that get three spaces to drive in it?
It depends on your DM how they rule that. The rules for dnd 5e Difficult Terrain say that “You may move at half speed in difficult terrain.” Therefore, 25 becomes a speed of twelve for purposes of moving through difficult terrain.
If you are applying a map with 5ft squares, then this may not divide nicely. So ask your DM. You might allow them to move two squares, one round and then three the following.
The Rule: (PHB 182)
You may move at half speed in difficult terrain. It means moving 1 foot in difficult terrain costs 2 feet of speed.
Types of Difficult Terrain in dnd 5e
It may vary from thick forests, deep marshes, rubble-filled wrecks, cliffs, and snow-covered Grounds. All are difficult terrain 5e examples.
The DMG appends webs as on (p105) and climbing on a giant creature(p.271) to this listing. Also of record are ball bearings and caltrops. (PHB, which does not perform difficult terrain per se. But walking through a square of either one at half movement (as if treating it as difficult terrain) opposes the other effect of these hazards. Then, some spells make an area into difficult terrain. Still, since various of these and mainly simulate one of the products mentioned above, there is no need to address them specifically.
Dense Forests: are difficult to push through, cause you to have to loop around, snag on your clothes, etc.
Deep Swamps: are troublesome to push through, cause you to have to loop around, your feet get grounded in the mud, etc.
Rubble-filled Ruins: cause you to have to loop around, might shift under your weight, etc.
Steep Mountains: require more energy to traverse, may cause you to have to backtrack or climb vertically, could trigger rockslides, etc.
Ice-covered Ground: walking slower helps you to avoid slipping and falling.
Webs: taking care by moving helps you not to become stuck and restrained by the web.
Climbing on Larger Creatures: the constantly shifting, unpredictable surface hampers movement.
Ball Bearings and Caltrops: It occurs by moving slowly. So it lets you dodge stepping on something you wish to avoid.
Some examples decrease movement because the creature moving must be careful of a danger (Rubble-filled Ruins, Ice, Webs, Ball Bearings, and Caltrops). Others reduce activity by actively impeding progress (Dense Forests and Deep Swamps). Others because crossing the terrain is physically more demanding (Steep Mountains & deep Swamps).
What about Large Creatures in 5e difficult terrain?
An essential thing to consider when handling a large creature moving through difficult terrain are:
Is the terrain still difficult at that size?
Regular stairs would be challenging for a Tiny creature but wouldn’t be for a Small or more giant monster. Similarly, some steep facades may not present a predicament for an animal large enough to step up to the following level. Also, tall grass may appear like a Dense Forest to a small creature. A Thick Forest may resemble no more than tall grass to a sufficiently large animal. The depth of a swamp is also relative to the size of the creature crossing it. Things like slipperiness and bypassing uncertainties would still be difficult for most animals, no matter how large or small they are.
How does the large creature move?
Is the size of the peril small enough for the giant monster to bypass by passing over it? If they miss noticing it, would it probably still impede their movement, such as getting them to slide or get stuck?
In such cases, where it would, where the creature’s feet are? Suppose it is a bipedal monster, such as an ogre, troll, or giant. Their feet are close to the center of the spot they occupy. And manage them as triggering the dangerous terrain their space is within the affected area. You may assume that their feet are held at the corners of the square for a quadruped creature. What about a monster that slinks or has many legs? In that case, they may either trigger the outcome in their total area they occupy or repeal it entirely, based on the situation.
Another smart way to check this is to roll Percentile Dice. Suppose the number moved is abrupter than the percent of the monster’s squares that occupy the unmanageable terrain in d&d. They approach it as difficult terrain in 5e. Otherwise, it does not apply. That is the more reliable way to do it when logic does not strictly recommend another explication.