A fantasy first person combat game, that is fully physics enabled.
Anything can be damaged and destroyed, where larger objects are comprised of multiple subsystems. If a specified number of supporting subsystems (defaults to 1/2) are destroyed, the supported subsystem also collapses.
All but the smallest items when destroyed turn into debries. (Which could be also damaged and destroyed).
Contact with a moving object inflicts damage, how much depends on the mass and speed of the object, while the damage type depends on the shape of the object.
This means that debries of a collapsed subsystem can damage other subsystem, potentially starting a chain reaction that brings the whole structure down.
Armor would work similarly to armor in old-XCOM, giving both resistances and armor rating. Resistances are percentil, by which the damage is multiplied, then the armor rating is subtracted from the damage, if the resistance used is less than 100% (If the armor does not protect from a damage type or even makes you weak to it, then it does not slow it down).
HP of an object (or a subsystem) depends on it's material and mass, while it's resistances and armor rating depend only on it's material. A stone wall will be tougher than a wooden wall, but more vulnerable to blunt damage.
On creatures, armor would be their naked Resistance and AR, plus that of any clothes they happen to wear.
The protection would be applied separately on each layer, starting from the outside.
Ex. Human wearing a Gambson and Full Plate is hit with a Warhammer for 20 Blunt damage.
The full plate has 99% Blunt and 10AR. The damage is reduced to 10 Blunt
Gambeson has 50% Blunt and 2AR. The damage is reduced to 3 Blunt
Human skin has 99% Blunt and 1AR. The human takes 2 damage.
Ex2. The same human is hit with a fire based attack for 15 Fire damage
Full plate has 100% Fire, damage not reduced.
Gambeson is flamable, 125% Fire. Damage is increased to 19 Fire.
Human skin has 99% Fire, 1 AR. Human takes 18 damage.
Armor also takes any damage that passes through it, but tends to have more HP than those wearing it. Many weak hits will eventually peel armor off people, but strong hits will generally kill the victim first.