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Archives of Nethys

Archives of Nethys

Pathfinder RPG (1st Edition) Pathfinder RPG (2nd Edition) Starfinder RPG

Rules Index | GM Screen | Player's Guide
Guns & Gears / Gears Equipment

Siege Weapons

Source Guns & Gears pg. 72 2.0
Shattering towering palisades. Mowing down hordes of soldiers. Breaking through barred castle gates. All of these tasks call for something heftier than the typical armaments carried by the common soldier: siege weapons. These massive, often-complex devices require full crews to operate. In significant numbers, they allow attackers to lay siege to entire fortifications, just as their name would suggest.

There are two categories of siege weapons: mounted and portable. Mounted siege weapons take up a certain size and space, typically have defensive statistics, and are used for large-scale warfare. More adaptable are portable siege weapons, such as battering rams, which can be carried more easily and can serve a valuable role during large-scale warfare, smaller conflicts, or even exploration.

All siege weapons need more than one person to operate them, working together as a crew. These crew members all need to be adjacent to the siege weapon for it to operate. A siege weapon's stat block lists the minimum number needed and the maximum crew size. Adding additional crew beyond the minimum is useful for ensuring a quick and successful Load in uncertain conditions and allowing for enough time to Aim the siege weapon when firing at a moving target.

Siege Weapons vs. Normal Weapons

Many of the benefits that apply to standard weapons— daggers, bows, battleaxes, and the like—don't work on siege weapons. They're simply too different in form and function. The GM might allow using them in certain circumstances, but this is fairly rare.

Character abilities that affect their attacks might work with portable siege weapons. For example, a battering ram might get the benefit of a character's bonuses that apply to attacks with two-handed weapons. The GM can determine what's reasonable and what's not. Because siege weapons require special actions to operate, a character can't use their special actions with them. Sorry, no Attacks of Opportunity with a battering ram!

Building Siege Weapons

Just like other items, building a siege weapon requires using the Craft activity. However, due to the size, it typically takes more than one person to prepare some of the materials (such as felling tall trees and working them to create a trebuchet arm) and assemble the weapon. You typically need a number of workers equal to the minimum crew size for the siege weapon to complete it in the standard amount of time. It can take much longer or even be impossible for a smaller team or individual. Due to their specific uses, you might be able to use Engineering Lore or Warfare Lore instead of the Crafting skill when you Craft a siege weapon. The GM determines whether you can—some strange or more complex engines might not be constructible with Warfare Lore.

Disassembling and Reassembling

A mounted siege weapon without a Speed must be disassembled to be moved, then reassembled in its new location. The GM determines how long this takes, but it's typically 1 day or half a day of downtime to disassemble a siege weapon and 1 to 2 days to rebuild it. As with building a siege weapon, you need a larger crew to disassemble or reassemble a siege weapon at full speed.

Disabling Siege Weapons

Disable a Device can be used to deactivate most siege weapons that have complex moving parts. This typically doesn't require thieves' tools, takes one success, and uses the standard DC for the item level of the siege weapon.

Mounted Siege Weapons

Source Guns & Gears pg. 72 2.0
Properly using a mounted siege weapon involves three activities: Loading, Aiming, and Launching the payload. Generally, none of these activities can be taken unless the weapon has enough crew, but the GM might allow a smaller crew or even an individual to perform simpler parts of the process, like Launching—especially at a dramatic moment!

Aiming

Source Guns & Gears pg. 72 2.0
A cumbersome mounted siege weapon can't be Aimed in a moment like a bow could be. A member of the weapon's crew needs to take the Aim activity to adjust a mounted siege weapon's aim. At a given time, the weapon is Aimed in a particular way, depending on the target or area the weapon uses.
  • Single Target: Aimed at one square
  • Burst: Aimed at one grid corner (that will be the center of the burst)
  • Cone or Line: Aimed in a particular direction, to the nearest 45º angle.
When a siege crew member takes the Aim activity, they can move the aim of a mounted siege weapon only a certain distance (or rotate the weapon a certain amount for a cone or line). Typically, the aim for a single target or burst can't be placed too close to the weapon due to the arc in which the weapon shoots. The distance moved or rotated can be found in each weapon's stat block, as is the minimum distance, if applicable. The Launch entry notes whether the attack is against a single target or in a burst, cone, or line.

Loading

Source Guns & Gears pg. 73 2.0
Any member of the crew can take the Load activity to prepare the weapon, resetting its machinery or helping Load the payload. The stat block lists how many times the activity must be taken to prepare the weapon to Launch. Some Load activities require successful checks to be effective, such as ones that require an Athletics check to Load heavy ammunition into the siege weapon. Once the weapon is Loaded, trying to Load it further has no effect. It doesn't matter in what order the siege weapon is Aimed and Loaded, and the crew could partially Load the weapon, Aim it, and then continue Loading it without disrupting the process.

Launching

Source Guns & Gears pg. 73 2.0
A member of the crew adjacent to the siege weapon's release can use the Launch action to shoot the siege weapon. After the weapon has been Launched, it must be Loaded fully to be Launched again. No matter how quickly it's Loaded, a single siege weapon can never be Launched more than once per round. The aim remains where it was, and the weapon needs to be Aimed again only if the crew wishes to change the aim. Launch [one-action] (attack) Requirements The siege weapon is Loaded; Effect The siege weapon launches its payload, which targets or has an area where the weapon is Aimed.
  • Single target Targets a creature, unattended object, or structure in the square the weapon is Aimed at
  • Burst Centered on the grid corner the weapon is Aimed at
  • Cone or Line Directed where the weapon is Aimed
Each creature, unattended object, and structure the siege weapon is Aimed at or that is in the area takes the amount of damage listed in the Launch action, with a basic saving throw against the DC listed in the stat block. If you're trained in any weapons of the category listed in the siege weapon's proficiency entry, you can use your class DC instead of the weapon's default save DC. The weapon's range increment penalty applies to the Launch DC, as does your multiple attack penalty. If the weapon is mounted on a vehicle, the penalties for attacking from a vehicle in combat also apply. Though a siege weapon doesn't require an attack roll, the Launch action still has the attack trait and therefore counts toward your multiple attack penalty.

Moving a Mounted Siege Weapon

Source Guns & Gears pg. 73 2.0
A mounted siege weapon has to be built on solid ground and remains stationary while being operated. Some are on wheels or are otherwise easier to move, but none can be prepared or shot while being moved. The GM might allow a mounted siege weapon to be placed on a large enough vessel, such as a sailing ship.

Moving a mounted siege weapon takes concerted effort from the whole crew pulling and pushing. This requires acting in concert, as described under Portable Siege Weapons, with the crew leader taking the Move Siege Weapon activity. This requires the minimum number of crew required to operate the siege weapon and gets no extra benefit for additional crew helping. If a siege weapon doesn't list this action, it can't be moved this way; it has to be disassembled and reassembled.

Move Siege Weapon [one-action] Requirements The rest of the crew have Readied to Stride on your order; Effect You and the crew Stride, moving the mounted siege weapon with you. The maximum distance equals the slowest crew member's Speed, or the maximum Speed listed in the siege weapon's Move Siege Weapon entry, whichever is lower. The siege weapon's aim moves the same distance and direction the siege weapon moved.

Portable Siege Weapons

Source Guns & Gears pg. 73 2.0
Portable siege weapons require moving in concert and making a single attack supported by the full crew.

Acting in Concert

Source Guns & Gears pg. 73 2.0
Because portable siege weapons require coordination, operating one requires following a crew leader. The rest of the crew must Ready an action to be taken when the crew leader calls to attack with the siege weapon. The siege weapon's special activity lists what action they need to Ready. For example, all of the crew operating a battering ram—except the crew leader—need to Ready to Stride. Each portable siege weapon has a special activity the crew leader can take if all the rest of the crew have Readied the necessary action. The number of actions it requires and the other specifics can vary greatly depending on what it takes to operate the weapon. It typically requires the crew leader to make a Strike.

Striking

Source Guns & Gears pg. 73 2.0
A Strike with a siege weapon uses the crew leader's attack bonus. The siege weapon's Proficiency entry indicates the weapon category for the siege weapon. The crew leader rolls an attack roll against the target. Any bonuses or penalties the crew leader is taking apply to the attack roll. See the sidebar above for more on how attack abilities work with portable siege weapons.

Bulk

Source Guns & Gears pg. 74 2.0
A portable siege weapon has a Bulk entry. This is primarily used when someone is carrying the portable siege weapon around. When it's being used by a crew, this Bulk is distributed among them as they see fit, and it's usually not worth tracking the Bulk unless they're already heavily loaded. If characters try to have more than one of them carry the portable siege weapon when it's not being used (dragging it around a dungeon, for example), this is cumbersome, and they're encumbered due to the challenge of constantly coordinating their movement.

Siege Weapon Statistics

Source Guns & Gears pg. 74 2.0
A siege weapon uses the following stat block format. An individual siege weapon might omit some of these sections, especially a portable siege weapon.

Siege Weapon Name Item [Level]

Rarity Size Mounted or PortableOther Traits Price This entry lists the siege weapon's Price; Ammunition If the siege weapon requires special ammunition, the ammunition's name appears here, along with the Price and Bulk of each piece.
Usage This entry shows whether the siege weapon is mounted or held. The number of hands required for a held siege weapon reflects how many the entire crew needs to use to operate the weapon; Bulk A portable siege weapon has Bulk; Space A mounted siege weapon has this entry to indicate its dimensions, not including any creatures crewing it.
Crew The number of creatures needed to operate the siege weapon is listed here. If additional creatures can assist, there's a second number to indicate the maximum number that's practical. For instance, “4 to 8” indicates the weapon can't be operated by fewer than four creatures, and that no more than eight creatures total can crew the weapon at a time; Proficiency This entry shows the proficiency required to use your class DC when Launching a mounted weapon (see the Launch action) or the proficiency used for your attack roll with a portable siege weapon.
AC The siege weapon's AC. This section appears only if the siege weapon can normally be attacked and is more typical of mounted siege weapons; Saving Throws The siege weapon's saves, which typically include only Fortitude and Reflex.
Hardness The siege weapon's hardness; HP The siege weapon's Hit Points, with its Broken Threshold in parentheses; Immunities The siege weapon's immunities; Weaknesses The siege weapon's weaknesses, if any; Resistances The siege weapon's resistances, if any.
Speed This is the maximum Speed you can move the mounted siege weapon using the Move Siege Weapon activity.
The description of the siege weapon.
Aim The entry for Aim shows the distance a creature can move the aim by taking this activity and the minimum distance away from the siege weapon the aim can be placed. Load This entry shows how many actions the Load activity takes and how many times this must be done to finish Loading the weapon. Launch This gives the specifics of the Launch action, including the traits, damage, size and shape of the area, and default DC.

Related Rules

Black Powder Siege Weapons (Source Guns & Gears pg. 172 2.0)