Destructible Terrain

Most structures can be broken, as your typical village hut is not made of adamantine. In order to destroy a structure, and in the absence of specialized explosive devices, you generally have to take it apart piece by piece.

These variant rules can be used for dismantling those pesky structures, like that guard post those goblins are hiding in. Consider each tile that contains a wall a separate entity, which can each be attacked independently.

Basics of Wall Stats:

Using these variant rules, each 5 foot length of a wall (typically representent by an individual grid square) has its own stats. While that sounds like it'd be a chore, this template is to ensure that tracking the damage to sections of a wall is made much more simple. A few constants are as follows:

Immunity : All walls are immune to psychic and poison damage, and cannot be afflicted by conditions or moved.

: All walls are immune to psychic and poison damage, and cannot be afflicted by conditions or moved. Damage Threshold: Every 5 foot length of wall has a damage threshold, this is further explained below.

Here are some example wall stat blocks:

Wooden Wall : 10 AC, 15 HP, 8 Damage threshold.

: 10 AC, 15 HP, 8 Damage threshold. Stone Wall : 12 AC, 30 HP, 16 Damage Threshold, Immunity to fire, poison, and necrotic damage.

: 12 AC, 30 HP, 16 Damage Threshold, Immunity to fire, poison, and necrotic damage. Metal Wall : 15 AC, 70 HP, 36 Damage Threshold, Immunity to fire, poison, and necrotic; resistance to piercing and slashing damage from nonmagical weapons.

: 15 AC, 70 HP, 36 Damage Threshold, Immunity to fire, poison, and necrotic; resistance to piercing and slashing damage from nonmagical weapons. Tent/Cloth Wall: 8 AC, 8HP, vulnerability to fire.

Damage Thresholds:

Damage Thresholds are applied to each wall piece, at a value that is one above half the total HP of that wall section. This is to make keeping track of damaged wall sections easier. A wall section is either unharmed (superficially scratched), damaged, or destroyed. If an attack hits a section of wall but the attack's damage does not exceed the damage threshold, that attack is considered to superficially damage the wall in some way.

The reason damage thresholds are set at just over half of the walls total HP, is to represent that walls may have three states: undamaged, damaged, or destroyed.

If a wall has had its damage threshold exceeded once, it would be impossible for it not to be destroyed if it had the damage threshold exceeded again.

Resistances and Vulnerabilities

Certain building materials are more or less susceptible to certain types of damage. When assigning stats to your structures in this manner, keep in mind real qualities of materials (i.e. clay walls are made to absorb heat, and would then be resistant or immune to fire damage. Mud walls are good at absorbing concussive shocks and would therefore be resistant to thunder damage.) Keep in mind that the DM allocates resistances and vulnerabilities, and they needn't all be assigned prior to play. For example, if the DM determines the stone wall will be resistance to slashing damage, then one player asks if he can use Acid Splash to try to eat away at the wall, the DM may determine that the stone wall is then vulnerable to acid damage, as that would be sensibly realistic.

Structural Supports

Walls are generally made to support things like ceilings, archways, etc. Therefore, if a wall can be broken, so too can the things it supports. However not every section of a wall is vital for structural support. In order to replicate this, you can assign certain portions of wall as critical support sections. It is recommended to do this privately, as the players generally won't know exactly where to attack a building to topple it.

The larger the building the more numerous the support sections. If a building has more than one support section, the building may not topple when only one is felled. Roll a d20 to determine how much damage the building sustains, with a DC equal to 12 + the number of remaining support sections (i.e. a barracks with 6 support sections in the walls loses a support. Roll against DC 17). If the d20 roll exceeds the DC, the building collapses. A lower roll will result in the support section and all structural pieces connected to it on the grid collapsing. If all support sections in a given building are destroyed, the building collapses.

Siege Equipment

Certain weapons are designed specifically for sieging and destroying structures. In order to show this trait, when using these variant rules, and siege equipment, designate the number of wall sections a siege engine strikes simultaneously (i.e. factoring that each section is a 5 foot length of wall, a trebuchet may simultaneously strike as many as 5-8 conjoined sections of wall. A Ballista is more precise and may only strike 2-4.)

Author credit: Pikeman Pete