The visibility of variables in Lua is a bit different than in C#. The same variable name can be used within the inner block without any naming issues. Lets see how this is in practice

If a variable is declared and the outer-most scope it will be considered a global one. A scope of variable is defined from it’s declaration to the last instruction in the same block as the declaration.

x = 10 -- global variable
do -- new block
local x = x -- new 'x', with value 10
print(x) --> 10
x = x+1
do -- another block
local x = x+1 -- another 'x'
print(x) --> 12
end
print(x) --> 11
end
print(x) --> 10 (the global one)
view raw scope.lua hosted with ❤ by GitHub

The local x = x defines a new variable with new scope and with initial value taken from the outer scope.

Variables can also be accessed within the functions defined within their inner scope.

a = {}
local x = 20
for i=1,10 do
local y = 0
a[i] = function () y=y+1; return x+y end
print(a[i]())
end
view raw inner_functions.lua hosted with ❤ by GitHub

Al the anonymous functions (10) share the same variable x with value 10 but each of them has a separate variable y.