# Conditions

A **Condition** is a synchronous check that returns `true` or `false` without changing game state. Use checks such as *is the door locked?* or *does the player have the key?* to decide whether Instructions branch, loop, wait, restart, or exit.

![Condition inside the Event component](assets/conditions.jpg)

## Anatomy

Each Condition has three controls beside its title:

| Control | Effect |
| :--- | :--- |
| **Enabled** | A disabled Condition is skipped and treated as passing. |
| **Breakpoint** | Pauses the editor when the Condition is evaluated. |
| **Sign** | Inverts the result. The title updates to show the word **not**. |

Use the **Sign** toggle when the opposite Condition doesn't exist. Inverting one check produces forms such as *is not active*, *does not have the tag*, and *is not a child of*.

![Condition with an inverted sign](assets/conditions-invert-sign.jpg)

## Combining Conditions

A Conditions list combines its entries with **AND** by default: every Condition must pass for the list to pass. Add each required check to the same list to combine them.

An empty list passes. This means an **If** with no Conditions always runs, and a **Wait Until** with no Conditions returns immediately.

!!! info "Some Instructions expose OR"
    The underlying system supports OR as well as AND, and some Instructions expose it. Where it isn't exposed, express *either or* by nesting a second **If** inside an **Else**, or by building the choice into a single Signal.

## Where Conditions appear

The Instruction or Signal containing a Conditions list decides how to use its result:

| Host | Uses the result to |
| :--- | :--- |
| **If** | Decide whether to run its nested Instructions. |
| **Else If** | Decide whether to run its nested Instructions when the preceding branch didn't run. |
| **While** | Decide whether to run the loop body again. |
| **Exit** | Decide whether to end the list. |
| **Restart** | Decide whether to jump back to the top. |
| **Wait Until** | Decide whether to stop waiting. |
| **Wait While** | Decide whether to keep waiting. |
| **Conditions** | Combine a nested group with AND or OR. |
| **Filter** | Decide which entries to include in a [collection](../signals/collections.md). |

![Conditions with an If and an Else](assets/conditions-if-else.jpg)

Conditions also appear inside components from other packages. You can add them to your own components when designers need to configure a check.

**Compare Numbers** offers equal, not equal, less than, less than or equal, greater than, and greater than or equal in one Condition.

!!! tip "Boolean evaluates any Bool Signal"
    The **Boolean** Condition takes any Bool Signal and passes when it's `true`. Because Signals compose, this Condition can evaluate nested calculations without a dedicated Condition for each case.

## Evaluation cost

Conditions run synchronously and return before the frame continues. Comparisons and tag reads have little cost.

Conditions that search the scene or resolve a Signal that performs a physics query do more work. A **While** checks its Conditions before each iteration, and a **Wait Until** checks every frame, so repeated evaluation can add up.

!!! warning "Wait Until polls"
    **Wait Until** and **Wait While** re-evaluate their Conditions once per frame until the answer changes. Use them for inexpensive checks; an expensive Signal repeats its work every frame.

    Where possible, use a [binding](../signals/bindings.md) so the Event reacts to the change instead of polling for it.

## Try it

* Add an **If** with a **Compare Numbers** Condition and log a different message on each side of the check.
* Flip the Condition with the **not** toggle and watch the two branches swap.
* Stack two Conditions in the same **If** and confirm both must pass.
* Replace them with a single **Conditions** Condition set to **OR** and confirm either now passes.
* Set a breakpoint on a Condition and inspect the values it's comparing while the editor is paused.

## Where to go next

- **[Control flow](control-flow.md)** — use Conditions in branching, looping, waiting, and exits.
- **[Signals](../signals/index.md)** — supply the values that Conditions compare.
- **[Conditions reference](../reference/visual-scripting/conditions/index.md)** — inspect every generated Condition entry.