# Game Rules

Jurassic Saga adds its own vanilla game rules, which let you tune breeding, metabolism, machines and fences without touching config files.

All of them are set with the standard `/gamerule` command and require operator permissions (OP level 2 or higher).

---

## Available game rules

| Rule | Type | Default |
|---|---|---|
| `jsDropEggs` | boolean | `true` |
| `jsMetabolism` | boolean | `true` |
| `jsFeederDrain` | boolean | `true` |
| `jsPlantSpread` | boolean | `true` |
| `jsFencesAlwaysOn` | boolean | `false` |
| `jsIgnoreBuildingConstraints` | boolean | `false` |
| `jsMachineSpeed` | integer | `50` |

---

### jsDropEggs

**Syntax:** `/gamerule jsDropEggs <true|false>`
**Default:** `true`

Controls whether extant animals periodically lay eggs on their own, the way vanilla chickens do.

This affects the [Ostrich]($content/fauna/extant/ostrich), [Alligator]($content/fauna/extant/alligator) and [Reed Frog]($content/fauna/extant/reed_frog). It has no effect on extinct creatures, which are only obtainable through the DNA pipeline.

```
/gamerule jsDropEggs false
```

---

### jsMetabolism

**Syntax:** `/gamerule jsMetabolism <true|false>`
**Default:** `true`

Controls whether creatures consume food and water.

When disabled, creatures never become hungry or thirsty  useful for creative building.

```
/gamerule jsMetabolism false
```

---

### jsFeederDrain

**Syntax:** `/gamerule jsFeederDrain <true|false>`
**Default:** `true`

Controls whether [Feeders]($content/machines/feeder) consume their stored food when they dispense it.

When disabled, feeders serve creatures without depleting their supply, giving you effectively unlimited food. Applies to the herbivore, carnivore and aquatic feeders.

```
/gamerule jsFeederDrain false
```

---

### jsPlantSpread

**Syntax:** `/gamerule jsPlantSpread <true|false>`
**Default:** `true`

Controls whether prehistoric plants spread to nearby blocks on their own.

When disabled, plants stay exactly where you put them.

```
/gamerule jsPlantSpread false
```

---

### jsFencesAlwaysOn

**Syntax:** `/gamerule jsFencesAlwaysOn <true|false>`
**Default:** `false`

Allows [Fence Poles]($content/blocks/fence_poles) and their cables to stay electrified without a power source.

```
/gamerule jsFencesAlwaysOn true
```

---

### jsIgnoreBuildingConstraints

**Syntax:** `/gamerule jsIgnoreBuildingConstraints <true|false>`
**Default:** `false`

Removes the placement restrictions applied when running wire between fence poles, letting you connect them freely.

```
/gamerule jsIgnoreBuildingConstraints true
```

---

### jsMachineSpeed

**Syntax:** `/gamerule jsMachineSpeed <value>`
**Default:** `50`

Sets how much progress machines make per tick  the value is added to a machine's progress counter each tick, so **higher is faster** and the relationship is linear. Doubling it halves the processing time.

Affects the [Genetic Analyzer]($content/machines/genetic_analyzer), [DNA Modifier]($content/machines/dna_modifier), [Incubator]($content/machines/incubator) and [Flora Cultivator]($content/machines/flora_cultivator). Nests use half this value.

<Callout variant="warning">
    This rule has no enforced minimum or maximum. Very large values finish everything almost instantly, and `0` stops
    the affected machines entirely.
</Callout>

```
/gamerule jsMachineSpeed 100
```

---

## Examples

**Creative building**  no hunger, no food drain:

```
/gamerule jsMetabolism false
/gamerule jsFeederDrain false
```

**Faster testing**  double machine throughput and skip fence wiring rules:

```
/gamerule jsMachineSpeed 100
/gamerule jsIgnoreBuildingConstraints true
```

**Tidy park**  stop plants from creeping into your paths:

```
/gamerule jsPlantSpread false
```

---

## Growth speed is not a game rule

There used to be a `jsFasterGrowth` game rule. It was removed in v0.2.2 and replaced by the **`entityGrowthRate`** config option, set in the mod's settings rather than with a command.

| | |
|---|---|
| **Default** | `5` |
| **Range** | `0.5` – `10` |
| **Meaning** | `1` equals one real-life year of growth per half hour in-game |

Higher values grow animals faster.

---

## Notes

- Game rules are stored per world and persist across restarts
- Changes take effect immediately, with no restart required
- Run `/gamerule` with no arguments to list every rule, vanilla and modded
- The `js` prefix stands for "Jurassic Saga"

---

<Callout variant="info">
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</Callout>