forgive me ahead of time if this is the wrong category, but:
Hello, again, dev forum. I have a question.
is there a limit to how many parts can be in one game?
this has been in my mind for 2 days, and I am unsure.
I can’t find anything similar on the developer forum, nor can I find anything on the developer hub.
If there was a limit, a looped Instance.new(“Part”) would eventually stop, so no.
However it’s in your interest to make sure all computers can handle your environment, at least with minimal graphics settings.
There’s not really a limit to how many parts can be in a game, although of course if you add too many parts to a game, it can impact performance.
Roblox BaseParts are optimized and are more efficient to use, so you can get away with using a lot of these types of parts. If they’re unanchored, they will have physics which if you have too many unanchored parts can also impact performance due to the physics simulation calculations.
Unions are special types of parts and sadly are heavily unoptimized by the Roblox rendering engine. Roblox, from my educated guess, do not optimize rendering Unions so for example, if you have 10 of the exact same Union, Roblox will send each single one to the graphics card to be individually processed - but this can be massively improved.
This means that using a lot of Unions may impact performance in a significant way.
There’s also MeshParts which are fairly efficient and Roblox are constantly improving this as the engine improves. The nice thing about these is that you can create your meshes in Blender and import them into Roblox for use in your game. Really useful for props and parts of your map, etc.
So, although there’s no strict limit to the amount of parts you can have, you should consider the performance impact of each type of part and how you plan to use it. I’ve included references to each of these in this post in hopes to provide further information about them and how you can use them.
Hope this helps 
And yes, Unions are an obsolete hell.
Yes and No.
While you can have infinite parts, having too many parts close to each other will lag the game.
I was pretty confused too if Unions helped or harmed performance, so thanks for clarifying that, too. ;o;
and thank you to everybody for helping. ^v^