Demolition & Collapses    The Damaging Objects rules describe how a party might overcome a barrier with damage. However, destroying any important part of a building or ruin risks structural failure. In battle, powerful attacks - particularly AoEs and ZAoEs - can also have dangerous side effects on the surroundings. This chapter describes the consequences of such collapses, how to rescue characters trapped in them, and how to avoid them... or deliberately cause them.

    Collapse rules assume a large, solid structure that can cause meaningful damage via its collapse. Flimsy structures such as tents or thatched huts need not apply these rules.

    Collapse rules are handled by zone (see Combat); in general, combat rules are used for most activities within ongoing collapses, due to the danger and time constraints. Each zone's collapse is described in one of X degrees of severity. Debris Strikes    Each degree of collapse has a chance to endanger characters with falling debris at certain intervals. In all cases, characters may roll a 2d12 on DEX to evade a debris strike; though similar to a combat defense roll, it is not considered a defense roll for any +TN purposes. If the roll is failed, the character is struck by debris; they take damage equal to the result of a roll given below by structure weight, with drive double the damage (roll separately for each character). Injury types from this damage are determined using the same d20 injury roll as ranged attacks, and do not dismember or cause bleeding. Vehicles are always struck, and take Structural Failures.

    Characters are also knocked down when struck, regardless of damage or drive. If they fail the 2d12 on DEX by 10 or more, they are pinned by the debris; they cannot recover from the knockdown until freed. They can attempt to free themselves by rolling d20 on STR as a major action, but can only attempt this once per minute. Grouped-up allies may also attempt this roll as a slowing major action without the minute limit, freeing the pinned character on any success.

    Debris strikes (both their chance of occurring, and their effects) are resolved at the beginning of the round, immediately after any fire hazard rolls. Any rolls listed to determine the timing of events within collapses are hidden rolls made by the GM.

Burial    All degrees of collapse beyond 1st eventually result in the zone fully failing. When this final collapse happens, characters unfortunate enough to still be in the zone face damage similar to the earlier debris strikes, but more severe: All characters are struck with damage equal to the result of a roll given below for structure weight, with drive double the damage. Characters receive a 2d12 roll on DEX, but do not evade this fate on a success, instead merely halving the damage (and drive). Injury/failure types follow the same rules as debris strikes.

     Once the damage is resolved, characters are buried in the rubble. Depending on structure weight (see below), they may be able to free themselves with a STR roll, or they may require General Labor process actions for their rescue. They function as paralyzed, except that they may make the listed STR rolls to free themselves; each roll costs 10 fatigue to attempt, takes 1 minute, and may be repeated until the character is free or has failed twice. Characters may have limited number of minutes or hours of air supply, especially in underground collapses. Suggested General Labor point goals to rescue all characters who cannot free themselves are given below by structure weight, but may vary significantly with the size and context of the collapse. Suggested point goals assume a 1 hour roll interval.

Structure Weight    The exact damage of debris strikes and burial, as well as how hard it is to escape burial, depends on the weight of the structure that has collapsed. While any structure heavy enough to use collapse rules is incredibly dangerous to be in during a collapse, heavier structures are even more so.

Collapse Points    Each zone with a possibility of collapse tracks collapse points, which are accumulated by certain events that compromise the integrity of the structure. For every 10 collapse points accumulated, the zone enters 1 degree of collapse. Points above 50 have no extra effect.

    Events can continue to contribute collapse points, potentially worsening a collapse in progress. For example, if a structure takes 20 collapse points, it will begin a gradual collapse (2nd-degree), but will shift to a catastrophic collapse if it takes 20 more. Existing debris strike intervals are replaced by those of the new degree, including the first-round strikes. The time until the complete collapse is also determined by the new degree's rolls, except in the unlikely case that the previous timing called for an earlier round.

    Some collapse point rules refer to armor range or critical damage. Copy these values from the Damaging Barriers rules, for whatever the zone's major structural walls and supports would be. The armor range will typically come from the middle column (>1"), and the wood, stone, or steel rows. Consider the armor range first for any rule here referring to damage, and apply the damage resistances listed for barriers.

    Rather than a fixed amount of points, most sources of collapse points are unpredictable, and roll dice for the number of collapse points they contribute:

    Collapse points can be significantly mitigated by Precise Demolition (Technology), or amplified by Efficient Demolition. Compromising a wall or door joining two indoor zones will contribute collapse points to both. At the GM's discretion, AoEs in the middle of a large ground-floor room (i.e. far from any walls) may contribute lessened or no points, though many such rooms rely on support pillars and will not see this reduction. Blast and frag damage from an explosive is considered to be all one AoE.

    Once caused, collapse points can generally only be removed by long General Labor process actions to repair and reinforce the structure.