Is there a difference between this
local a = Instance.new(t, p or game.Workspace)
and this
local a = Instance.new(t, (p or game.Workspace) )
In this case, there is no difference. However, if you wanted to say something like this:
local r = false local a = Instance.new(t, (r and p or game.Workspace) )
It's better to have parentheses for expressions with several and's and/or or's