---
title: boolean - Booleans
summary: Values true and false. Only false and nil are false in Lua conditions. Zero, an empty string and an empty table are true. Check the exact API contract.
section: reference
kind: guide
status: reference
updated: 2026-10-26
tags: ["API","X4"]
sources: ["https://wiki.egosoft.com/X4%20Foundations%20Wiki/Modding%20Support/","https://www.lua.org/manual/5.1/manual.html","https://luajit.org/ext_ffi_api.html"]
---
## Meaning

Values true and false. Only false and nil are false in Lua conditions. Zero, an empty string and an empty table are true. Check the exact API contract.

## Example

```lua
local ready = false
if not ready then
  ready = true
end
```

**What happens:** ready becomes true because not false is true.

This fragment does not print or write a log message. The values shown are the expected results of the example.

## Methods and related calls

[API reference](wiki:api-index).