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Siege Warfare

Siege Engine Information from Ultimate Combat

Siege Warfare
The Death of Simon de Montfort at the siege of Toulouse (25 June 1218) Alphonse-Marie-Adolphe de Neuville (1835-1885)

All siege engines are at least size Large devices and often much larger. Unless stated otherwise in an individual siege engine description, all siege engines use the following rules.

Proficiency: Siege engines are exotic weapons. A creature with the Siege Engineer feat is proficient with all siege engines, including siege firearms. A creature that is proficient in firearms is also proficient in siege firearms, but not other siege engines.

Crew: The sheer size of a siege engine often necessitates a crew for its use. One person of that crew is the crew leader. Usually the crew leader targets or controls the movement of a siege engine; sometimes the crew leader does both. Often the crew leader is required to take actions and make specific checks in order for a siege engine to function. The rest of the crew members are required to spend actions and make checks in order for a siege engine to function.

The number of members in a crew assumes Medium creatures. A ram can be crewed by Small creatures, but it takes double the crew to do the same job. If Large or larger creatures serve as crew members, each Large creature counts as four crew members, a Huge creature counts as eight Medium creatures, a colossal creature counts as 16 Medium creatures, and a gargantuan creature counts as 20 Medium creatures.

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 twice 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 siege 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. 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 armor bonus 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.

Moving Siege Engines: Siege engines have a speed. The speed of a siege engine is the distance it can be moved if its full crew makes a move action to move it. Some siege engines have a speed of 0. If this is the case, the engine must be dissembled before movement is possible, or else mounted on a vehicle. Siege engines that are atop or mounted on vehicles move with those vehicles.

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

Critical Hits: When a direct-fire siege engine or a close assault siege engine scores a critical hit, it confirms the critical and deals critical hit damage just like any other weapon. If an indirect-fire ranged siege engine rolls a natural 20 on its targeting check, it can also score a critical hit. The crew leader must reroll the targeting check to confirm the critical. If the confirmation targeting check is successful, the attack is a critical hit, and the siege engine multiplies its damage by its critical multiplier. 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.

Mishaps and Misfires: Rolling a natural 1 on an attack roll or a targeting check made by an indirect-fire ranged siege engine produces a mishap. Usually a mishap applies the broken condition. A non-firearm siege engine with the broken condition takes a -2 penalty on attack rolls, targeting checks, and damage rolls. It also moves at half its normal speed. If the creature that serves as crew leader has the Siege Engineer feat, that creature does not generate a mishap on a natural 1 when firing the siege engine. Firearm siege weapons do not gain a mishap on a natural 1, but instead have a misfire value, like other firearms do. An attack roll or targeting check that falls within the misfire range causes the firearm siege engine to misfire. A misfire always misses, and applies the broken condition to the siege engine firearm. A firearm siege weapon with the broken condition takes all of the penalties and limitations that non-firearm siege engines do, and the misfire range of the firearm siege engine is increased by 4. If the firearm siege engine already has the broken condition when it misfires, it explodes. When a firearm siege engine explodes, it deals its damage to all creatures within a blast range (those within the blast can attempt a DC 20 Reflex save for half damage). The normal misfire range of a firearm siege engine and its blast range are given in the individual firearm siege engine description. Crew leaders with the Siege Engineer feat do not lower the misfire value of firearm siege engines.

Constructing and Repairing Siege Engines: A siege engine is a complex device requiring a DC 20 Craft (siege engine) skill check to build or repair.

Siege Engine Assembly
Engine SizeTime RequiredWorkers Required
Small1 minute1
Medium10 minutes2
Large1 hour4
Huge2 hours6
Gargantuan4 hours8
Colossal8 hours12

Disabling Siege Engines: A siege engine is considered a difficult device to disable, requiring 2d4 rounds of effort and a DC 20 Disable Device check to do so. When a siege engine is disabled, it either doesn’t work or is sabotaged and stops working 1d4 minutes after use. Fixing a disabled siege engine requires a DC 20 <ahref=”https://spiralworlds.com/skills/skill-craft/”>Craft (siege engine), Disable Device, or Knowledge (engineering) check. It takes 10 minutes to fix the device, and the check can be retried if the fix fails.

Assembling Siege Engines: Siege engines are broken down for transport and can be reassembled on the battlefield, requiring the time and number of workers noted below. Each assembly worker must make a DC 10 Craft (siege engine) check; if untrained, they may not take 10. Assembly can be performed with at least half the required number of workers by doubling the time required. If fewer than half are available, the weapon cannot be assembled.


Siege Engine Qualities

The carronade. Daniel Vierge, from Ninety-three vol. 1, by Victor Hugo, London, New York, 1889.
The carronade. Daniel Vierge, from Ninety-three vol. 1, by Victor Hugo, London, New York, 1889.

The following are the various entries on the equipment tables for siege engines (given in the column headings on Tables: Ranged Siege Engines and Close Assault Siege Engines). While ranged siege engines use most of these entries, close-assault siege engines only use some of them.

Cost: This value is the siege engine’s cost in gold pieces (gp). The cost includes gear needed to work the engine as well as gear for upkeep. Typical ammunition costs and weights are given in siege weapon description.

Damage: This column gives the damage typically dealt by the engine. If the engine has a special mode of attack or damage, this space is marked by the words ‘see description. If the siege engine does not deal any damage, but rather is a tool for getting close to or over fortifications, this entry features a dash (—). Some ranged siege engines can be loaded with special ammunition that affects or overrides the weapon’s typical damage or range. As large and imprecise weapons, siege engines do not deal sneak attack damage or any other kind of precision damage.

Critical: The entry for this column notes how the engine is used with the rules for critical hits. Unlike normal ranged weapons, siege engines can deal critical damage to objects as well as creatures.

Range: Any attack at more than the distance listed in this entry is penalized for range. Beyond this range, the attack or targeting check takes a cumulative -2 penalty for each full range increment (or fraction thereof ) of distance to the target. Some siege engines have a minimum range for effectiveness. If that is the case, the range of this weapon is followed by a parenthetical with the minimum range, followed by the abbreviation “min.”

Type: Like weapons, siege engines that deal damage are classified according to the type of damage they deal: B for bludgeoning, P for piercing, or S for slashing. Some engines deal damage of multiple types. Some special siege engines (like the firedrake and the firewyrm) deal energy damage, typically fire damage. In those cases, the type of energy damage is listed instead.

Crew: This column gives the number of creatures needed to properly use the siege engine, assuming Medium creatures. Some siege engines can be used with a smaller crew, but there are usually consequences such as slower aiming, firing, or movement.

Aim: This column gives the number of full-round actions (or move actions if the crew leader has the Master Siege Engineer feat) required to aim a siege engine. If the siege engine is being controlled by less than its normal crew complement, the number of actions it takes for the crew to aim the siege engine is doubled.

Load: This column gives the number of full-round actions (or move actions if the crew leader has the Master Siege Engineer feat) required to load a siege engine.

Speed: This is how fast the siege engine can be moved with move actions made by its entire crew.

Ranged Siege Engines

Ranged siege engines assault structures and people from a distance, by propelling ammunition in some fashion. Siege engines hurl massive projectiles in one of two ways: direct fire or indirect fire. Both take a number of actions to load or aim, and the basic rules are described below.

Load Ammunition: In order for a ranged siege engine to fire, it needs to be loaded with ammunition. Loading ammunition takes a number of full-round actions depending on the siege engine (this time can be reduced to move actions if the crew leader has the Master Siege Engineer feat.

Aiming a Siege Engine: Ranged siege engines must be aimed in order to attack a desired target (in the case of direct-fire siege engines) or square (in the case of indirect-fire siege engines). Aiming takes a number of full-round actions (or move actions if the crew leader has the Master Siege Engineer feat, with the number depending on the specific siege engine. Aiming a siege engine with a diminished crew doubles the amount of time it takes to aim the siege engine. Each time a new target or square is chosen as the target of a siege engine’s attack, that engine must be aimed anew.

Direct-Fire Ranged Siege Engines: Direct-fire weapons launch their projectiles on a relatively flat trajectory, allowing them to more easily target creatures or pummel barriers directly in front of them. A direct-fire weapon uses a normal attack roll, with the normal penalty for nonproficient use. In addition, a direct-fire weapon takes a -2 attack roll penalty per size category that the weapon is larger than the creature aiming it. Creatures that have ranks in Knowledge (engineering) or use a targeting platform (see below) are not adversely affected by their size when firing direct-fire ranged siege engines. Sheer manpower can also reduce the penalties for size. Increasing the crew of these weapons by 1 or more can reduce the attack roll penalty for creature size: as long as an extra crew member is no smaller than three size categories smaller than the direct-fire weapon, it can reduce the penalty due to the aiming creature’s size by 2. For example, a Huge ballista fired by a Medium creature that is part of a crew of two (the creature aiming the ballista and someone to help position it) takes only a -2 penalty on attack rolls.

Indirect-Fire Ranged Siege Engines: Indirect-fire weapons launch projectiles in high arcs toward their targets. They typically lob heavier missiles and payloads than direct-fire weapons, but they are harder to aim accurately. Indirect weapons can bypass many forms of fortification, delivering their payloads of solid shot, scatter shot, or even disease-ridden offal to targets beyond the walls of castles. They can also be used to batter fortifications where they are most vulnerable, arcing down on towers and walls, crushing them with the weight of stone or raining down smaller projectiles on a wall’s defenders. Indirect-fire weapons use a targeting mechanic similar to that described for catapults, hereafter referred to as an indirect attack. The following is an update to those rules.

Indirect Attack: To fire an indirect-fire ranged siege engine, the crew leader makes a targeting check against the DC of the siege engine. This check uses his base attack bonus, his Intelligence modifier (if not trained in Knowledge [engineering]) or Knowledge (engineering) skill modifier (if trained in that skill), any penalty for not being proficient in the siege engine, and the appropriate modifiers from Table: Indirect Attack Check Modifiers. If the check succeeds, the ammunition of the indirect attack hits the square the siege engine was aimed at, dealing the indicated damage or effect to any object or creature within the area of its attack. Creatures may get a saving throw to limit the effect of the attack; this is typically based on the type of ammunition used.

If the attack misses the intended square, roll 1d8 to determine in what direction the shot veers. A roll of 1 indicates the ammunition falls short (toward the siege engine), with rolls of 2 through 8 counting squares clockwise around the target square. Roll 1d4 for every range increment at which the attack was made (1d4 if the target square is within the engine’s first range increment, 2d4 if the target square is within the second range increment, and so on). The total is the number of squares by which the attack misses, with the direction in which the squares are counted determined by the d8 roll. The ammunition deals its damage and any other effects in the square it lands on.

Indirect Attack Check Modifiers
ConditionModifier
No line of sight to target square-6
Successive shots (crew can see where most recent miss landed)Cumulative +2 per previous miss (maximum +10)
Successive shots (crew can’t see where most recent missedCumulative +1 per previous miss (maximum +5) shot landed, but observer is providing feedback)
Successive shots after a hit+10

Siege Weapon Descriptions

The following are siege weapon descriptions.

A weapon with two types is both types if the entry specifies “and.”

Special Siege Engine Ammunition

The following kinds of ammunition can be used either in select types of indirect-fire siege engines, or with cannons. The ammunition description specifies which types of siege engines use the special ammunition. The costs and weights on Table: Special Siege Engine Ammunition are for individual uses of special ammunition.

Special Siege Engine Ammunition
AmmunitionCostWeight
Alchemical fire200 gp10 lbs.
Blast shot30 gp25 lbs.
Bomb600 gp30 lbs.
Chain shot50 gp30 lbs.
Liquid ice400 gp20 lbs.
Plague bundle80 gp20 lbs.
Smoke shot250 gp20 lbs.

Alchemical Fire: This hard, ceramic canister of alchemist’s fire can be used as ammunition in catapults and trebuchets. When it hits its target square, it deals 4d6 points of fire damage to each creature and wooden structure within 5 feet of the target space, and each creature must make a DC 20 Reflex saving throw or catch on fire (wooden objects automatically catch on fire). Every creature and wooden object within the area between 5 and 30 feet of the target space must make a DC 20 Reflex saving throw or take half the fire damage, but they do not catch on fire. On a siege engine mishap, this ammunition explodes before it is launched, dealing its damage to the siege engine and all nearby creatures and wooden objects as if one of the spaces of the siege engine (crew leader’s choice) were the target square. This alchemical fire ignores the hardness of wooden objects.

Blast Shot: Instead of a single hard ball, this ammunition is a bundle of large pellets, balls, or pieces of scrap metal, propelled a short distance by black powder and attacking all creatures and objects within an area. Both cannons and fiend’s mouth cannons can fire this kind of ammunition. When such a siege engine fires this ammunition, it hits every creature and object within a 30-foot-cone burst. The siege engine makes attack rolls against each creature and unattended object in the burst. It must miss every creature or target to misfire, and a misfire generates the normal effect. It deals its normal damage on a hit, but does not ignore the hardness of objects.

Bomb: A bomb is a metal canister filled with metal balls and black powder that can be used as ammunition in catapults and trebuchets or carried by two Medium creatures or one Large creature to its destination. A bomb either explodes on impact (if fired from a catapult or trebuchet, or within 3 rounds of a fuse being lit if carried). When it explodes, it deals 6d6 points of piercing and bludgeoning damage to all creatures and objects within 30 feet of the target square. On a siege engine mishap, this ammunition explodes before it is launched, dealing its damage to the siege engine and all nearby creatures and wooden objects as if one of the spaces of the siege engine (crew leader’s choice) were the target square. It ignores the hardness of wood and stone.

Chain Shot: This siege engine firearm ammunition can be loaded in a cannon or a fiend’s mouth cannon. It is especially good at tearing through sails and dirigibles (see Vehicles), dealing double its normal damage to those forms of propulsion. When fired at a creature, on a hit, the creature must succeed at a DC 20 Fortitude saving throw or be knocked prone.

Liquid Ice: This hard, ceramic canister filled with alchemical liquid ice can be used as ammunition in catapults and trebuchets. When it hits its target square, it deals 4d6 points of cold damage to each creature within 5 feet of the targeting space, and each creature must make a DC 20 Fortitude save or become entangled for 1 round. Every creature within the area between 5 and 30 feet of the target space must make a DC 20 Fortitude saving throw or take half damage. On a siege engine mishap, this ammunition explodes before it is launched, dealing its damage to all nearby creatures as if one of the spaces of the siege engine (crew leader’s choice) were the target square.

Plague Bundle: This hard, ceramic canister is filled with a noxious mass of diseased carrion and offal that can be used as ammunition for a catapult or a trebuchet. It deals only half damage, but every creature hit by it is exposed to filth fever. A GM might allow a plague bundle to inflict other diseases.

Smoke Shot: This hard ceramic sphere contains two alchemical substances separated by a thin barrier, much like a smoke pellet in larger form. When it hits the targeting space, it deals 2d6 points of damage to any creature in that space, and the substances mingle and then create an area of foul but harmless yellow smoke radiating 30
feet from the target square. Treat the effect as a fog cloud spell. On a siege engine mishap, the ammunition explodes before it is launched. Its effect is centered on one of the spaces of the siege engine (crew leader’s choice).

Close Assault Siege Engines

While most siege engines attack at range, some are used up close to directly undermine defenses, batter through them, or otherwise bypass them. Some close assault weapons are not even weapons at all, but instead provide means for assault forces to protect themselves or circumvent fortifications without destroying them.

Close Assault Siege Engines
 CostDmgCriticalType1CrewSpeed
Bridge, assault
Large1 gp
Huge10 gp
Gargantuan50 gp
Colossal250 gp
 CostDmgCriticalType1CrewSpeed
Corvus
Corvus100 gp1Special
 CostDmgCriticalType1CrewSpeed
Gallery
Large250 gp315 ft.
Huge500 gp615 ft.
Gargantuan1,000 gp915 ft.
Colossal2,000 gp1815 ft.
 CostDmgCriticalType1CrewSpeed
Ladder, escalade
Large5 gp2as crew speed
Huge10 gp4as crew speed
Gargantuan50 gp6as crew speed
Colossal250 gp8as crew speed
 CostDmgCriticalType1CrewSpeed
Ram
Large500 gp2d6x3B515 ft.
Huge1,000 gp3d6x3B10 15 ft. 
Gargantuan2,000 gp6d6x3B 20 15 ft.  
Colossal5,000 gp10d6x3B 40 15 ft.  
 Cost DmgCriticalType1CrewSpeed
Siege tower
Large1,000 gp615 ft.
Huge2,000 gp1215 ft.
Gargantuan5,000 gp2415 ft.
Colossal10,000 gp4815 ft.

Structure Hardness and hit points

While armies can use siege weapons against troops, usually the goal of a siege engine is to demoralize foes and pound their structures to rubble. The following rules give the statistics for various buildings and barriers that are often the targets of siege engine attacks. They are split up into three different categories: buildings, gates, and walls.

When any of these structures gain the broken condition, their hardness is halved, along with any other effects of the broken condition.

Buildings

Der Runde Turm in Andernach. Aquarell auf Whatman-Velin. 20 x 13,7 cm Date 1844 Anton Ditzler (1811-1845)
Der Runde Turm in Andernach. Aquarell auf Whatman-Velin. 20 x 13,7 cm Date 1844 Anton Ditzler (1811-1845)

Buildings are sizable structures with many hit points and very poor ACs (a Large building is AC 4, a Huge building is AC 3, and a Gargantuan or larger building is AC 0). When a building is reduced to half its hit points, it is broken-it still stands, but only partially. It can be easily entered, and for all intents and purposes it has been breached. Reducing a building to 0 hit points completely destroys that building. Creatures inside the building suffer the effects of a cave-in.

All these building statistics assume that the structure’s inside is somewhat hollow but sturdily built, with enough space for its occupants to walk around inside. Flimsy buildings have half the hit points of the buildings detailed in Table: Buildings. Buildings can be magically treated, like dungeon walls and doors can. Doing so doubles their hardness and hit points. Magically treating a building costs 5,000 gp for a Large building, 10,000 gp for a Huge building, 20,000 gp for a Gargantuan building, and 40,000 gp for a Colossal building. A spellcaster with the Craft Magic Arms and Armor feat can magically treat buildings.

For larger buildings, put together multiple buildings of these sizes and add the hit points together.

Buildings
MaterialHardnessHit Points
Large
Hit Points
Huge
Hit Points
Gargantuan
Hit Points
Colossal
Wood51202709603,240
Stone82004501,6005,400
Iron or steel104009003.20010,800
Adamantine205601,2604,48015,120

Gates

Markttreiben unter einem Torgebäude. Öl auf Eichenholz. 36,5 x 27,5 cm. Date by 1897 Adrianus Eversen (1818-1897)
Markttreiben unter einem Torgebäude. Öl auf Eichenholz. 36,5 x 27,5 cm. Date by 1897 Adrianus Eversen (1818-1897)

Gates serve as the entrances and exits to fortified structures, and are typically the weakest spots in any fortification’s defenses. Gates are at least Large, but can be as large as Colossal. It typically takes three full-round actions to open or close a Large gate (up to three creatures can work together to close a Large gate as a full-round action), and larger gates typically take at least a minute to close or open. Gates have ACs based on their size (a Large gate is AC 4, a Huge gate is AC 3, and a Gargantuan or larger gate is AC 0).

Gates can be magically treated. Doing so doubles the hardness and hit points. Magically treating a gate costs 2,000 gp for a Large gate, 4,000 gp for a Huge gate, 8,000 gp for a Gargantuan gate, and 16,000 gp for a Colossal gate. A spellcaster with the Craft Magic Arms and Armor feat can magically treat gates.

Gates can be attacked and damaged, or they can become broken (as the condition) with a successful Strength check, usually as a result of ramming. When a gate gains the broken condition, it is effectively breached, and can be moved through as if it were an opening one size smaller.

Gates
MaterialBreak DC1HardnessLarge Hit PointsHuge Hit PointsGargantuan Hit PointsColossal Hit Points
Wood35560135240540
Stone388100225400900
Iron or steel24102005008001,800
Adamantine48202806301,1202,520
1 The DC assumes the gate is size Large and is barred and locked. Huge doors increase the break DC by 5, Colossal doors increase the DC by 10, and Gargantuan doors increase the DC by 15. Arcane lock increases the DC by 10.

Walls

Regensburger Schiffslände, Aquarell, 28 x 23 cm Date 1872 Anonymous
Regensburger Schiffslände, Aquarell, 28 x 23 cm Date 1872 Anonymous

The walls that guard castles and cities are sturdy fortifications, usually constructed in a series of 5-foot squares. A square of wall has an AC of 5, and hardness and hit points equal to its type.

Squares of walls can be magically treated. Doing so doubles the hardness and hit points. Magically treating wall squares costs 500 gp per wall square. A spellcaster with the Craft Magic Arms and Armor feat can magically treat walls.

When a wall gains the broken condition, its hardness is halved, but the wall is not breached. Only destroying a section of wall allows it to become breached. When a square of wall is breached, any sections directly above it fall onto the missing section of walls. Doing this reduces the falling wall section to half its current hit point total -1, which applies the broken condition to that square of wall.

Walls
MaterialHardnessHit Points per 5-Foot Square
Wood530
Stone845
Iron or steel1090
Adamantine20120

Section 15: Copyright Notice – Pathfinder Roleplaying Game Ultimate Combat

Pathfinder Roleplaying Game Ultimate Combat. © 2011, Paizo Publishing, LLC; Authors: Jason Bulmahn, Tim Hitchcock, Colin McComb, Rob McCreary, Jason Nelson, Stephen Radney-MacFarland, Sean K Reynolds, Owen K.C. Stephens, and Russ Taylor.

Defence Devices

Ultimate Equipment Guide II

Author Greg Lynch, J. C. Alvarez

Publisher Mongoose Publishing

Publish date 2005

The following section lists all tools and engines the Siegemaster has designed for the defence and fortification of buildings. They range from increased protection measures to strange devices designed for equally strange defensive tactics.

Given their size and often stationary quality, defence devices have no weight rating listed.

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