What's the difference between mouse_check_button and pressed?

mouse_check_button: true every frame while held. mouse_check_button_pressed: true only the first frame of the press. mouse_check_button_released: true only on the release frame. Edge vs level triggers.

How do I implement key/button repeat?

Use mouse_check_button + a cooldown timer. On press, fire and start cooldown; while held, fire when cooldown elapses. Classic auto-repeat after initial delay.

Why does pressed fire on every step in some code?

Maybe you’re calling it in a loop within a single step, getting cached state. Or accidentally using mouse_check_button (held) instead of mouse_check_button_pressed. Re-read the function name.

Fix: GameMaker Mouse Check Button Pressed No Repeat

Quick answer: _pressed is edge-triggered (first frame only) by design. For auto-repeat, use mouse_check_button with a cooldown timer.

A spell-casting RPG wants holding the mouse to fire repeatedly. mouse_check_button_pressed only fires on the initial click. Holding does nothing further. Expected behavior, but you want auto-repeat.

Trio of Functions

mouse_check_button: true every frame while held. Level trigger.
mouse_check_button_pressed: true only on the press frame. Edge trigger.
mouse_check_button_released: true only on the release frame. Edge trigger.

Pick by intent: pressed for single actions (clicking a button); held for charging or continuous fire.

Auto-Repeat Pattern

// Create event
fire_cooldown = 0;
initial_delay = 15;   // frames before repeat starts
repeat_rate = 5;       // frames between auto-shots

// Step event
if (mouse_check_button(mb_left)) {
    if (mouse_check_button_pressed(mb_left)) {
        fire();
        fire_cooldown = initial_delay;
    } else if (fire_cooldown <= 0) {
        fire();
        fire_cooldown = repeat_rate;
    } else {
        fire_cooldown -= 1;
    }
} else {
    fire_cooldown = 0;
}

Initial click fires; then waits initial_delay frames before auto-repeating at repeat_rate cadence. Standard text-editor key-repeat feel.

Continuous Fire (No Initial Delay)

if (mouse_check_button(mb_left) and fire_cooldown <= 0) {
    fire();
    fire_cooldown = 3;   // 20fps autofire at 60fps
}
fire_cooldown -= 1;

Simpler shmup-style: fires at fixed rate while held. No initial delay.

Verifying

Click and release: one shot. Hold: shots after delay at expected cadence. Release: resets. Cooldown should not persist across releases.

“Pressed for edges, button for level, timer for repeats. Three pieces, every input idiom.”

For shooter feel, gate auto-repeat behind a screenshake / muzzle flash — even a constant cadence reads as ‘feedback’ when each shot has weight.