There are rules for variable names. A variable starts with a letter or an underscore. It can't contain anything other than letters, underscores, or digits. It also can't be one of the following reserved words of Lua:
and
break
do
else
elseif
end
false
for
function
if
in
local
nil
not
or
repeat
return
then
true
until
while
The following are valid variables:
The following are invalid variables: