It looks like you're new here. If you want to get involved, click one of these buttons!
I am used to set variables with an _ so it's language irrelevant.
I do it like this on several places and ways:
in script as: _setvar _variable VALUE or _variable VALUE
in lisp as (_setvar "_variable" VALUE) and (_getvar "_variable")
in COM (C#) as: AcadApplication.ActiveDocument.SetVariable("_variable", 1);
It now seems that in V20 you should no longer use the _ in the variable name.
the _variable VALUE as command still works, but all other no longer work.
Was this done intentionally? Is it described anywhere?