For example, on Spectrum nightclub some of the blocks have bright outlines
Really simple. It should be placed inside a PlayerGui but doesn't have to be. If it is placed in a PlayerGui it is local so only the player can see it.
1 | selection = Instance.new( "SelectionBox" ) |
2 | selection.Parent = script.Parent |
3 | selection.Adornee = script.Parent |
The Adornee property is very important. It is the part that the selection box surrounds itself around.