# Execution
###  Branch on Expression
The **Branch on Expression** response enables the user to evaluate an expression with the possible outputs of True or False each time the event connected to it is triggered. Once the response is executed, the result of the evaluation can be acquired through the **True** or **False** ports.
#### Example
In this example, a **Branch on Expression** response is used to evaluate an expression once the user triggers the object named Activate. The result of the expression, which will be either True or False, if the result was true, the object named "Variable\_01" will be shown, if it was false, the object named "Variable\_02" will be shown.
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### [](https://simlab-soft.com/help/uploads/images/gallery/2026-03/response-delay.png) Delay
[](https://simlab-soft.com/help/uploads/images/gallery/2026-03/UO0image.png)
**The Delay node** waits for the specified **Duration** (in seconds), then executes the node linked to its **Execute** output.
Duration can be an integer or a float less than one to achieve sub-second delays.
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###  Loop
The **Loop node** enables the user to repeatedly execute a connected response for a specified number of times as defined in the Number of Loops field. Each time the event connected to the loop is triggered, the response is executed repeatedly, and the loop continues until the assigned number of repetitions is completed.
#### Example
In this example, a **Loop node** is used to repeatedly execute the connected response that decreases the value of a number variable by one. The Decrement response is repeated for the number of times specified in the **Number of Loops** field, with the duration between each repetition set in the **Interval** field. Once the assigned number of repetitions is completed, the sound named **Countdown\_Over** plays.
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###  Run Script
The **Run Script** node allows the user to execute advanced functions using the **Lua programming language**. This node provides flexibility by enabling custom scripts to be triggered when an event occurs. Allowing for complex operations and logic to be carried out as defined in the script. This node is ideal for scenarios requiring functionality beyond the standard nodes, offering advanced customization and control over the system.
You can read about Lua Scripting in SimLab Training builder through the following Blog:
**[Lua Scripting Blog](https://blog.simlab-soft.com/lua-scripting-in-simlab-training-builder-from-beginner-to-beyond/ "Lua Scripting Blog")**
> **[Lua Documentation for SimLab Training Builder](https://www.simlab-soft.com/3d-products/docs/help/scripting/English/Lua/ "Lua Documentation for SimLab Training Builder")**
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### [](https://simlab-soft.com/help/uploads/images/gallery/2026-03/response-customevent-trigger.png) Trigger Custom Action
[](https://simlab-soft.com/help/uploads/images/gallery/2026-03/xylimage.png)
Calling this **Trigger Custom Action** will execute the corresponding [**Custom Action** event ](https://simlab-soft.com/help/link/581#bkmrk-custom-event%C2%A0)(based on the matching ID), passing along any optional information provided in the info field.
This is useful when you want multiple paths in your experience to produce the same response — without duplicating it each time.
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