TD path block prevention...

Not sure if this would be tagged "Trigger Help" or "AI Help"

-I'm working on making a new TD map and I was wondering if anyone had any suggestions as to a specific trigger layout.
-I am looking to prevent players from completely blocking off the pathing between the creeps spawn point and the creeps destination.
-You know, like when you build that last tower at the end of a row next to a wall and it prevents the creeps from passing thru.
-I'm guessing that the function of the trigger would be to either remove the blocking tower/nearby towers or order the creeps to start attacking.

Please post any trigger layouts that you know/think would work. ^_^


P.S. (It is also necessary that the pathing creeps do not attack between rounds. To do this I set all of the creeps "Attacks Enabled:" to "None" in the object manager. So ordering the creeps to attack in this case would do nothing... I guess just what I am looking for is any suggestions as to the right way to go about this. Thanks.)

What do you mean by trigger layout? I don't really understand your question.
For my map, i don't have a trigger for antiblock- i just have the creeps have 1000 siege damage and when you block they attack automatically.

I know that some maps use a little guy who runs through, I'm guessing that they use a system that if there's two little guys in the TD-Area <gen> something happens. I'm not that experienced with anti-block triggers since they tend to use automatically and if someone blocks, I don't care if all his towers die.

Theres one Difficult way and one easy way. The difficult way works with any map. And the easy way works on some maps. I don't know the difficult way. I need a screenshot of the minimap to see if you can do the easy way of anti-blocking.

To move the creeps I have the following trigger:
------------------------------------------------------------------------------

Event: A Unit enters the Playable Map area
Conditions: Unit is owned by Player 8 (the Computer controled NPC units)
Actions: Order entering unit to move to random point in region (a small region at the map's center)
------------------------------------------------------------------------------

-If I enable the creep's attack they attack immediately... reguardless of their being a path block or not. If there is a better way to do this please post.
-If I disable their attack and a player blocks their path they just sit there and die.
-I am trying to find a way triggers or not, easy or hard, THAT WORKS. and by works I mean only lets the creeps attack if they cannot travel from their current psoition to their said destination.

=Milkman, What is the little man trigger you mentioned? I had an idea of sending a small unit thru and then after X seconds (if little guy was not in map center) he bould explode dealing enough damage (targets allowed: enemy) to the units is a small radius to kill all player towers. But I was hoping there was a better way to do it.

=BinWolf, I attached an overview of my map. The creeps spawn at the four corner areas and follow the arrows made of grass to the center. The side areas are not used for the creeps path. Please post what you know of easy and hard ways

Please Help!!!

Please Help :(