Add Building Upgrade With Trigger?

[Noritox]

Okay for a town hall, I don't want it to be able to upgrade to a better town hall until an event happens.

Is this possible? Like, don't even show the player the upgrade option until an event happens?

 

[Lamby]

If its ok to show the upgrade option (but not make it possible until the event is done) then you could make a dummy unit that spawns for each player at the event that is a techtree requirement for the upgrade.

 

[Xienoph]

How flexible do you want this to be? You can make two exactly the same Town Halls, except that one of them has the extra upgrade option. After the triggering event, call replace unit on your Town Hall, replace it with the Town Hall with the extra upgrade.

Or, you can make a dummy ability that does the upgrade. Give it to the Town Hall, but disable it. Enable the ability after the triggering event. Make sure that you create a trigger to remove / disable the dummy ability and do the upgrade, once the ability is cast. You can base it off the "Change Gold / Lumber" Ability (or something like that) so that you can do resource checking easily.