Upgrade path precluding another

[Nano]

Hi guys,

first of all just wanted to let any of the admins know that i appreciate this great site, didn't feel the need to make an introduction thread though

Ok basically i'm working on a TD map and the theme is that i want people to have two different upgrade paths that they take.

i.e

                Path A                               Path B
 Type 1      Type 2     Type 3            Type 4      Type 5     Type 6 
Type 1+      Type 2+     Type 3+         Type 4+      Type 5+     Type 6+

And what i want to happen is every x amount of turns the player receives one lumber to spend on an upgrade.

They can choose something from either Path A or Path B. Assume they want something from Path A, and they choose Type 2. Next lumber they get, they want to spend it in Path A again, but i want to make it if they have Type 2 then they can't choose Type 1 or Type 3, but only Type 2+ (have the others greyed out).

Is there any way to do this?

 

[donut3.5]

Welcome to the Hive!
Anyways, onto business:
Use

• Player - Set Max Research Level to 0

For each of Type 1 and Type 3 when Type 2 is researched. This way, they can't upgrade those.
--donut3.5--

 

[PurplePoot]

You could make the upgrades require dummy units which you could then add/remove at your whim.