[chrispedersen]

I'm the only player I've ever seen use this tactic. I do so in a couple of ways.

1. chokehold provinces, especially chokehold provinces one removed from forts with an active patrol.

usually you want to be careful of unattended labs.. but you can cast the dome, and then destroy the lab, if you wish.

2. forts. Try this as pangea, with your pans stealthy.

finally there is one other very interesting use for the dome, useful for nations that have dominion kill skulpting capabilities such as arco, LA-Pythium, and Mictlan.

Build a lab.
Cast Horror Dome. With just enough blood for a short - medium duration. Start construction of castle.
surround your castle with heretics so no dominion will penetrate.
In a few turns, you will have the benefit of M3 without paying for it

After the dome expires, research your heart away.