Quick answer: Combine Key Is Down (modifier) with On Key Pressed (main key) in one event. Both conditions evaluated together.

A level editor wants Ctrl+S to save. On Key Pressed for S alone fires when you type. Need to additionally require Ctrl held.

Event Setup

On Key Pressed: S
Keyboard.KeyIsDown(Control)
    → SaveLevel

The combined conditions both fire on the same frame; action runs only when both true.

Avoid Default Browser Action

Ctrl+S triggers browser’s Save Page. Suppress via:

System → On start of layout:
    Browser → Execute JavaScript: "window.addEventListener('keydown', e => { if (e.ctrlKey && e.key === 's') e.preventDefault(); });"

Prevents browser from intercepting before C3 sees the press.

Multi-Key Combos

Ctrl+Shift+S: chain three conditions. Each Is Down + final On Key Pressed.

Mac Cmd Key

Mac uses Cmd instead of Ctrl. Detect platform:

Browser.UserAgent contains "Mac":
    Keyboard.KeyIsDown(Meta) & On Key Pressed S
else:
    Keyboard.KeyIsDown(Control) & On Key Pressed S

Verifying

Press S alone: no action. Press Ctrl+S: save triggers. No browser save-page dialog.

“Modifier + main key = AND condition. Use Key Is Down for the modifier, On Key Pressed for the trigger.”

For shipped games, also handle browser’s focus-loss alt-tab + shift behavior — consistent input across devices.