What is race condition?

[TheDoom_Boy (Tomi)]

What is race condition in Roblox?

[SomeFedoraGuy (Him)]

I believe it’s exactly as it says on Google, when multiple threads attempt to access the same value.

[HugeCoolboy2007 (omega)]

To add onto what @SomeFedoraGuy said, a race condition is essentially a script or program trying to access a value before it’s formally defined (usually because of a slight delay or something) and can cause some problems.

[TheDoom_Boy (Tomi)]

Is indexing a part in the workspace that has not yet been created a race condition?

[oddcraft18]

A race condition can be when multiple scripts change the same value.

Example 1:

Script1: Change player speed to 20, and set it back to what was just recorded after 3 seconds.
Script2: Change player speed to 200 until the user completes this jump, then set it back to the recorded value.

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Result: You get a small speed boost, you get a big speed boost, you lose both speed boosts, and the game is softlocked. If you somehow win, then you get a permanent small speed boost.

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Example 2 (Duck Life Treasure Hunt):

Chest: Stop, play an animation, then go.
Morph: Stop, show a tutorial, wait for user input, then break the tutorial ui and run a sequence of speed changes.

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Result: You get a morph, the chest animation plays, and you start moving despite the wooden tutorial not exploding and the game not being ready.

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Race conditions can be gamebreaking and cause things like the game running at the wrong speed or a softlock, as well as other issues.

[Spacerator (NikiKITAECA)]

Yes, this definitely counts. One thread expects the part to exist, but the other one hasn’t made it yet. The first thread errors, and your game breaks. The first thread dying might also cause something in thread 2 to malfunction (if they’re codependent).