Incendiary shell

The incendiary shell is a type of mortar shell that explodes into a conflagration, dealing flame damage and setting the area alight.

Acquisition

Incendiary shells can be crafted at a machining table once the mortars research project has been completed. Each requires 10 Steel, 20 Chemfuel, 800 ticks (13.33 secs) of work modified by the general labor speed of the crafter, and a crafting skill of 4. The steel cost is increased to 20 if the Classic Mortars difficulty option is enabled.

They can also be purchased from traders.

Usage

Product	Ingredients	Type [ExpandCollapse]
IED incendiary trap	2	Building - Security

Summary

White, the radius of the shell's AoE when fired or when a single shell cooks off. Gold, radius when an entire stack cooks off.

When fired from a mortar, incendiary shells deal 10 Flame damage in a 2.9 tile radius. They also set the area on fire and creating chemfuel puddles which themselves burn.

When damaged beyond 70% of its health, it will explode after between 30 ticks (0.5 secs) and 60 ticks (1 sec), dealing 10 Flame damage in a radius around itself. The radius depends on the quantity in the stack, with a single shell covering a 2.9 tile radius, and expanding this radius proportional to the square root of the stack size times 0.4 up to a maximum radius of 6 tiles at a full stack of 25. Note that, unlike shells fired from a mortar, shells that explode from damage do not leave chemfuel puddles.

They are also used in the construction of IED incendiary traps.

Analysis

Incendiary shells are most useful against sieges - stationary targets with explosive mortar shells to light on fire. The fire makes it more likely to "hit" an explosive target than the use of regular high-explosive shells, but watch out for pawns with firefoam pop packs.

Otherwise, incendiary shells are of limited use. The other "main" target of mortars, stationary mechanoids, are completely immune to fire. For ordinary raids, fire spreads too slowly to be useful in combat. As mobile raiders are smart enough to avoid the flames, only a direct hit would cause damage. As high-explosive shells deal much more damage on direct impact, they're the superior choice. Note that the game will automatically cause rain if fires get too far out of control.

Sieges can and will use incendiary shells against you, which will ravage rooms floored with carpet, fields of plants, and storage rooms filled with flammable items. Firefoam poppers are ideal for protecting against fire. These incendiary shells that can also be looted once the siege is repelled - while crafting them typically isn't worthwhile, these shells are free and sometimes suboptimality can be outweighed by volume of fire.

Storage

As with all explosive items, these should be stored in separate storage containers. For maximum protection, put each stack of shells in a separate 1x1 stone box to prevent chain reactions. Pawns currently in a tantrum should be stopped at all costs, whether it be by arresting, creating another stockpile zone with a higher priority than the shell zone and prioritizing hauling the shells, or simply by shooting the pawn.

Gallery

One incendiary shell
Partial stack
Full stack

Version history

0.18.1722 - Added to replace mortar type system.
1.1 - crafting cost was increased (15 --> 20 steel and chemfuel cost).
1.3.3066 - Steel requirement decreased from 20 -> 10 unless Classic Mortar difficulty option selected.

Architect

Security: Barricade • Sandbags • Spike trap
(research): Autocannon turret • Foam turret • Mini-turret • Rocketswarm launcher • Uranium slug turret • Mortar
IEDs: IED trap • IED incendiary trap • IED EMP trap • IED firefoam trap • IED smoke trap • IED antigrain warhead trap • IED tox trap • IED deadlife trap
Related: Antigrain warhead • EMP shell • Firefoam shell • High-explosive shell • Incendiary shell • Smoke shell • Tox shell • Deadlife shell