I want to people cant build same(or upgraded) build

[egomanyak]

For example: a unit is "X"(wisp) can construct "Y"(and can be upgraded to "Z")
if i use limit trigger, "X" cant make "Y" if alredy have
but if X upgraded it to "Z", it can make "X" and there is one "X" and one "Z"

but i want to wisp can build only one "Y" or "Z"

and if it destroyed, i want to make can build again,

please put a demo map at the end.

 

[egomanyak]

*Go first page, my lord!*

 

[ZiggyMcjoney]

The only thing I can think of is to, after the wisp builds the structure, replace him with a wisp that cannot build the structure.

So you'd have to make two units in the object editor, one that can build it, one that can't.

When the structure is built, replace the unit that can build it with the one that can't.