Difficult Terrain

If a space is Difficult Terrain, every foot of movement in that space costs 1 extra foot. For example, moving 5 feet through Difficult Terrain costs 10 feet of movement. Difficult Terrain isn’t cumulative; either a space is Difficult Terrain or it isn’t.
A space is Difficult Terrain for a creature if the space contains any of the following:

• Creature that isn’t Tiny
• Furniture that is Small or larger
• Heavy snow
• Heavy undergrowth
• Ice
• Liquid that’s between shin- and waist-deep (any deeper and you need to Swim)
• Slope of 20 degrees or more
• Rubble
• Size smaller
• Pit or another gap of 2–5 feet
• Narrow opening that is sized for a creature one