Is it copy right to make a build system in my battle royale because fortnite has it

my cousin and brother thinks it is copy right

No, ideas can’t be copyright because they too much of abstract matter, at most they can be patent it, which i don’t think Epic did that. What is copyrighted are trademark (game tile, logos) and all the content and there design inside fortnite as well as the code it self. But as long as you recreate that build system with your own content and design, it is ok to do so.

Besides it not like fotnite is a first game with wall-based building system, same as Minecraft is not first block-based building game (Roblox was before Minecraft :p)

thanks

No, You won’t get copyrighted, that’s the beauty of playing roblox. I generally play roblox fps games - clones of CS-GO and it’s fun, takes up less memory.