How exactly does TD anti-block work?

My current solution is to more or less know the time it takes a unit to travel through a standard maze, send an invisible locusty unit through, if it does not make it within x seconds after the standard time, it is killed and a nuke is targeted at that place.

Problem #1: it would still be possible to just block off the passage with 5 towers and block the creeps with ease for at least half a minute, and when the nuke comes, you just rebuild the wall somewhere else, it only takes 5 towers.

Problem #2: maybe someone finds out a way to build a super gosu maze so long that the anti-block unit is still navigating through it when the timer is up, at which point their very good maze gets blown to pieces.

Problem #3: if the anti-block unit has no collision size, it goes through the towers. If it has a collision size, it may get stuck on slow(ed) heavy creeps that are still in the process of being killed, and end up timing out while still in the maze.

Much of this can be solved by putting the creeps on a timer so that if they take more than x seconds to get through, they are removed and the player loses a life. This would also improve lag. But of course, if someone builds a smart maze and the creeps time out on him he'd be understandably angry.

Besides, other TDs have no creep life timer.

Any suggestions?

Units issued a move order will automatically attack buildings that compeltely block it off. You just need to let the creeps attack.

Yeah, if the unit has a move order, then that order is destroyed when the unit gets stuck. At that time, the unit is without order, so it will now act on it's own, and the usual thing units do on their own is attack any nearby enemy.

All you need is a trigger that whenever a tower is destroyed, it orders the killing creep to move on (if the way is still blocked after 1 tower dies, the creep will simply stop again and destroy another tower). If more creeps get stoped in the time it takes one of them to destroy the tower, then you might want to order all the creeps in the vicinity to move on after a tower is destroyed, rather than only ordering the killing unit.

Cool, thanks! So I don't have to worry about anything and the people with anti-cheat detectors are noobs? ^_^