Siege Engines

Rules

Attack rolls: Direct-fire engines use normal ranged attack rolls, made by the crew leader, but use the Size modifier of the engine rather than that of the crew.
Indirect-fire engines aim at a location, not a creature, and make a Targetting check instead of an attck roll, which is a Know(Eng) check +BAB, DC 15 for a Light engine, 20 for Heavy engine. Indirect shots which miss scatter.
Attacks are made at the end of loading and/or aiming (meaning an even round from the beginning of the final loading/aiming action), and do not cost an additional action; the crew is free to take another action immediately after firing, at the same initiative count. The target is picked at the beginning of the aim action (since the shot is resolved an even round later, the target square may be empty or line-of-fire to the target creature lost in the meantime. The crew can choose not to take the shot, but may not shoot at something else without re-aiming).

Proficiency: Siege engines are exotic weapons. A creature with the Siege Engineer feat is proficient with all siege engines. Only the crew leader needs to be proficient.

Magical and Masterwork Siege Engines: Siege engines can be masterwork, increasing their Craft DC by 5 and costing an additional 300 gp. A masterwork siege engine can be enchanted at the cost for a normal magical weapon. The enhancement bonus of a siege engine applies on attack rolls and targeting checks (in the case of indirect ranged siege engines), and in the case of magical spell engines, the enhancement bonus also applies on damage rolls.

Defense and Hit Points: All siege engines are objects. A siege engine has a Dexterity of 0 (–5 penalty) and a further penalty based on its size. Each type of siege engine has its own hardness and hit points (typically Hardness 5, HP 20-80). Siege engines can be armored—treat the siege engine as a creature of its size to determine the cost of the armor. Masterwork siege engine armor can be enchanted for twice the normal cost to enchant armor. Armored siege engines have an AC equal to that normally granted by the specific armor (shields have no effect on a siege engine), a hardness and hit points equal to that of the armor, and bonus hit points equal to the armor bonus × 5.

Ranged Attacks: Unlike normal ranged weapons, siege engines do not deal half damage when attacking objects.

Critical Hits: Unlike normal attacks, siege engines attacks can deal critical hit damage to objects. Siege engines do not gain the benefit of critical feats the crew or the crew leader may have.

Stat Blocks

Weapon Size Damage Crit Range Req Crew Points Aim Load Speed
Light Catapult Large 3d8+3 x3 100 ft 28 1 1 5’
(w sling) 4d8+4 120 ft (ind)
Heavy Catapult Huge 6d8+6 x3 120 ft 32 1 2 5’
(w sling) 7d8+7 150 ft (ind)
Light Trebuchet Large 8d8+8 x2 80 ft (ind) 34 2 2 0’
Heavy Trebuchet Huge 12d8+12 x2 100 ft (ind) 60 4 2 0’
Light Ballista Large 6d8+6 19-20/x2 120 ft 32 1 2 5’
Heavy Ballista Huge 8d8+8 19-20/x2 120 ft 34 2 2 0’
Scorpio Medium 2d8+4 19-20/x2 120 ft 12 0 2 15’

Range: range increment (-2 to hit for each of these, as usual). Ind = indirect fire.
Req Crew Points: total number of crew points needed for a full crew. A creature’s Crew Points are calculated by taking 10 (no choice) on a Know(Engineering) check, using Strength bonus instead of Intelligence, and applying a 4x Size modifer. As little as half this number can operate the machine short-handed. Less than that cannot operate it at all.
Aim: number of full round actions to aim. The engine must be re-aimed if the target has moved since the last shot. Twice this if short-handed.
Load: number of full-round actions to load. Twice this if short-handed.
Speed: distance moved if the whole crew takes a full-round action to carry the engine. 0’ means they can’t pick it up; these must normally be disassembled to be moved.

Construction

Light Catapult
requires:
Wood (5sp, 200 lb)
Hemp Rope (1gp, 50’)
Sack & chaff (-)
optional sling:
Leather (-)
Twine (1cp, 10’)
Craft (siege weapons) DC 15
labor: 30gp

Heavy Catapult
requires:
Wood (1gp, 400 lb)
Hemp Rope (2gp, 100’)
Sack & chaff (-)
optional sling:
Leather (-)
Twine (1cp, 10’)
Craft (siege weapons) DC 18
labor: 50gp

Light Trebuchet
requires:
Wood (1gp, 400 lb)
rocks (-, 50x weight of projectile to throw)
Leather (-)
Twine (1cp, 10’)
Craft (siege weapons) DC 20
labor: 50gp

Heavy Trebuchet
requires:
Wood (2gp, 800 lb)
rocks (-, 50x weight of projectile to throw)
Leather (-)
Twine (1cp, 10’)
Craft (siege weapons) DC 22
labor: 60gp

Scorpio
requires:
Wood (12cp, 50 lb)
Hemp Rope (6sp, 30’)
Flax or Hemp or Skins (-)
Craft (siege weapons) DC 25
labor: 60gp

Light Ballista
requires:
Wood (1gp, 400 lb)
Hemp Rope (2gp, 100’)
Flax or Hemp or Skins (-)
Craft (siege weapons) DC 20
labor: 60gp

Heavy Ballista
requires:
Wood (2gp, 800 lb)
Hemp Rope (2gp, 100’)
Flax or Hemp or Skins (-)
Craft (siege weapons) DC 22
labor: 90gp

Siege Engines

Goblin Uprising thuddmonkey