Most actions you take in the game have an action cost. This determines how long it takes you to perform the action.
The standard action cost representing a "one-turn" action is 1,000. All action costs are randomly varied by up to ±10% in order to make the initiative order of the game less deterministic.
The most common action cost besides 1,000 is 100, "one tenth of a turn". Commanding companions has this action cost, as do various cases of flipping power switches.
| Mechanism | Amount | Scope |
|---|---|---|
| Empty the Clips | -50% | Firing pistols |
| Fastest Gun in the Rust | -25% | Firing pistols |
 medassist module
|
-80% | Applying tonics |
 micromanipulator array
|
-40% | Tinkering |
 plastifer chem vest
|
-100% | Applying tonics |
| Springing with Sprint | -67% | Movement |
| Short Blade Expertise | -25% | Attacking with a short blade in the primary hand
Using Hobble with a short blade equipped Using Shank with a short blade in the primary hand |
| Sprint | -50% | Movement |
 steel butcher knife
|
-50% (first) | Butchery |
| Telepathy | -90% | Commanding companions |
| Two-headed | -20% to -56% | Mental actions |
Modding note: at an internal technical level, this concept is referred to as "energy". "Action cost" is used in public facing materials to avoid confusion with things one thinks of first when thinking "energy".