Fragile Terrain (PSR Supplement)

**PSR** is an alternate ruleset compatible with most 5e content.
System Differences The Basics Time Shifts Phases The d20 Ability Check Ability Scores Strength Dexterity Constitution Knowledge Perception Charisma Saving Throws Skills Carry Slots	Encounters Group Turns Round‑Table Turns Staggered Turns Your Turn Move Action Bonus Action Reaction Making an Attack Unarmed Strike Sunder Defense Cover	Hit Points & Damage Temporary Hit Points Massive Damage Damage Types Max Damage Other Dangers Defeat Dramatic Death Common Hazards Extreme Climates Conditions Downtime Downtime Trading Downtime Enterprise	Items Goods & Currency Material Goods Weapons Improvised Attire Shields Tools Gear Attunement Objects Damaging Objects Hauling Objects Vehicles Artillery NPCs Mount Cohort Stat Blocks Vulnerability, Resistance, & Immunity Special Senses

Fragile terrain is a common hazard. It includes crumbling floors or thin ice that can only support a creature’s weight only momentarily.

If a creature uses any action on fragile terrain, or ends its turn there, the terrain crumbles away and the creature falls through, destroying a 5-foot square of the terrain directly underneath it. A creature can finish its action just before the floor gives away.
A Large or larger creature instead falls through fragile terrain as soon as it enters the space, and destroys a proportionally larger square: 10 feet for Large, 15 feet for Huge, and 20 feet for Gargantuan.
A Tiny creature instead doesn't fall through at all.
Any damage to a 5-foot square of fragile terrain, except psychic damage, destroys the square. Fragile terrain has 5 defense.