Why do game doors open so slowly? The hidden loading trick

November 7, 2026

In many games, a slow door is a loading door: a door that hides the time the game needs to load the next room. The door looks like part of the world, but it is really a loading screen in disguise. In Metroid Prime, a former developer said the doors were there to mask loading times.

What the game is doing

A game cannot always keep the whole world in memory at once. When you walk from one room to the next, the next room has to be loaded. If the game stopped to do that, you would see a loading screen. A loading door avoids that stop:

1. You walk toward a door. The game starts loading the room behind it.
2. The door is a gate. It stays shut, or opens slowly, while loading goes on.
3. When the room is ready, the door finishes opening and you walk through.

According to a former Retro Studios developer, Metroid Prime loaded at most two rooms at once. So the game only needed the current room and the next one, and the doors covered the gap between them.

The player does not read this as loading. They read it as a heavy door in a sci-fi base.

Why it works

Think about what the player would see without it. A frozen screen, a spinner, maybe nothing at all. A frozen screen makes players think the game crashed.

A door that is clearly moving tells the player the game is alive. They stay in the world and stay in the mood. The wait still exists, but it feels like part of the place, not a break from it.

This is a good example of a hidden trick that solves a technical limit with a design idea. The player never learns the rule. They just never see the loading screen.

Real games that use it

Metroid Prime is the best known case. In a 2022 interview covered by Siliconera, Retro Studios developer Zoid Kirsch said the reason doors worked that way was that Retro needed to mask the game's loading times. The same article says at most two rooms were loaded at once.

We link only that source here. Other games hide loading behind lifts, narrow gaps, or slow walking sections, but we only name a game when a developer has said so on record.

How to use it in your game

You can use the same idea in any game that streams its levels. A simple loading gate looks like this:

void OnPlayerNearDoor(Door door) {
    StartLoading(door.nextRoom);
}

void Update() {
    if (door.nextRoom.IsLoaded)
        door.Open();   // open only when the room is ready
}

Tips:

• Start loading early. Load when the player gets close to the door, not when they touch it. Often the door will open at full speed.
• Make the wait look natural. A door, a lift, a squeeze through a gap, or a long corridor all work. Pick one that fits your world.
• Give a sign of progress. A door that moves, a light that blinks, or a sound that rises tells the player the game is working.
• Do not hide long loads behind tiny doors. If the wait is many seconds, players will feel it. Show a real loading screen instead.
• Test on your slowest device, since the same door will feel very different on fast and slow hardware.

FAQ

Why do doors in games take so long to open?

Often the door is hiding a load. The game waits until the next room is ready before it lets you through, so you never see a blank loading screen.

Do loading doors still exist in modern games?

Yes, versions of the trick are still used wherever games stream levels from storage. Faster drives can shorten the wait, but the idea of hiding a load behind something in the world is still common.

What is a hidden loading screen?

It is any moment in a game that hides loading: a door, a lift, a tight gap, or a slow walk. The player is still playing, so it does not feel like a pause.

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