# Special effects

Source: https://storiara.com/glossary/special-effects
Last updated: 2026-09-14
Author: Nick Harty, Storiara

> Special effects, or SFX, are physical effects produced live on set while the camera rolls, such as rain, snow, wind, fog, fire, bullet hits, explosions, and breakaway glass or furniture. They are run by the special effects department, marked blue in a script breakdown, and are separate from visual effects added in post.

## Common SFX elements and how they show up in scripts

| Script says | SFX element | Notes for breakdown |
|---|---|---|
| "Rain lashes the windshield" | rain bars on car, water truck | wet-down, [wardrobe](https://storiara.com/glossary/wardrobe) multiples |
| "Fog rolls across the field" | fog/haze machines | wind direction, neighbors, fire marshal |
| "Bullets tear into the door" | squib hits, pre-scored door | armorer, safety bulletin, multiples of the door |
| "He smashes a bottle over his head" | breakaway bottle | stunt, [hero prop](https://storiara.com/glossary/hero-prop) clean version |
| "The fireplace roars" | gas fire bar | fire safety officer, location approval |
| "The car explodes" | pyrotechnics | permits, licensed pyro operator, may be VFX instead |
| "Her breath fogs" | cold room or VFX | decide early which |

Some of these, like fireplace fire and fog, are also on the [set dressing](https://storiara.com/glossary/set-dressing) or lighting side on smaller shows. Decide which department owns each one during prep so it doesn't fall between two.

## A breakdown example

```
88  EXT. HENDERSON FARM - BARN - NIGHT

    Lightning. Rain sheets off the barn roof. Cole kicks
    the lantern over and straw catches.
```

| Box | Entries |
|---|---|
| SFX (blue) | rain towers x2 over barn roof; lightning boxes (with electric); controlled straw fire, fire bars |
| Props | lantern (hero, and a rigged SFX version) |
| Stunts | Cole near open fire |
| Notes | fire permit, fire safety officer, water truck; night exterior; wet [greenery](https://storiara.com/glossary/greenery) and ground |

Two lines of script, and the scene needs water supply, a fire permit, and extra rigging hours before the shoot day. Lightning boxes are often a lighting department item, so the [gaffer](https://storiara.com/roles/gaffer) and the [special effects supervisor](https://storiara.com/roles/special-effects-supervisor) have to agree who supplies them.

## Scheduling and safety

SFX setups eat time. Rain has to be rigged, tested, and reset between takes, and wet actors need warm-up time and dry wardrobe. Breakaways need multiples and each reset means replacing the item, so budget the number of takes with the director. Anything involving fire, explosives, or firearms brings a [safety meeting](https://storiara.com/glossary/safety-meeting) and the matching [safety bulletin](https://storiara.com/glossary/safety-bulletin) on the call sheet.

## Deciding practical versus digital

Many script effects could go either way. The breakdown is where you mark a decision or a question: "car explosion: SFX or VFX, TBD with director." Leaving it blank means neither department budgets it. See [visual effects](https://storiara.com/glossary/visual-effects) for how VFX get tagged, and [stunts](https://storiara.com/glossary/stunts) for how performer actions around effects are split out.

## Frequently asked questions

### What is the difference between SFX and VFX?

SFX happen physically in front of the camera: a rain tower, a fire bar, a squib. VFX are created or altered in post: digital rain, a set extension, wire removal. Many shots use both, like a practical explosion enhanced with digital debris.

### Are rain and snow special effects?

Yes, when you make them. Rain towers, rain bars, snow machines, and fake snow blankets are SFX work. Real weather isn't, though it may call for a weather cover set.

### Who is allowed to run pyrotechnics on a film set?

Only licensed pyrotechnic operators, under the rules of the state or country where you shoot. Requirements differ by jurisdiction, and permits usually go through the local fire authority as part of the film permit.