Well the town deletion trick works best if you allow a construction worker/miner through to build a mine on the resource. At that point the AI will send a bunch of people to work the mine, but if you've reestablished your barricade then the AI will respond by deleting them. This means it's possible to completely wreck the AI's economy at the start of a game in a one on one match. Albeit this trick works best if you start with one resource near your own starting position.

Well, I did some more testing against two AI opponents with new kingdoms emerged active and learned that the AI will sometimes respond to this strategy by deleting entire villages. Albeit this only appears to happen when the AI attempts to send workers to setup a mine on it. This is because the AI will delete workers that get stuck trying to get through your market wall.

I also learned you can use science towers as well to create these barriers.

Maybe, but the cost of setting this trick up varies on how large the AI kingdom is. After all, you have to completely box it in. And this strategy gets even more costly if you have offensive Frythans active since you then need to defend your market wall. And if you have disasters on you'll need to store construction workers inside them as well.

Though, I'll admit it was pretty hilarious watching a bunch of Frythans reach my markets only to turn around and go home because their actual target was unreachable because of all of the markets I had set up.

I think this is a good tactic to trick the AI. But when faced with multiple kingdoms, the cost to the markets will actually be too much. You could keep a strong AI in check with it in order to fight weaker AIs more efficiently.

Well, I was messing around in 7K and learned that you can completely stump the AI by surrounding it's starting location with markets. After all, the AI isn't programmed to attack them. So, it will simply sit in place and do nothing.

Admittedly this isn't the most effective tactic since markets are expensive, but it is kind of funny to see the AI's inns and town surrounded by spies that are unable to go anywhere.

LOL