1 Tank versus 7 reavers.... guess who wins...... and yes the tank is inside the command center..... hehe..... no cheating required..... this is possible to recreate in a real game. Also notice the scarabs explode harmlessly......
Well this little trick makes siege tanks as strong as the structure they're sitting in. Making them very hard to kill with melee units and reavers who aren't controlled properly. Of course range units still have the ability to shoot back, making this trick worthless.... However it is possible to place a tank underneath a factory, hiding it from view, making it impossible to target with lock down or broodling. Also it is possible to stuff many tanks underneath with a bit of micromanagement, making 4 tanks, look like 1.
Ok to pull this off, you want to have a building that can lift off. place all the tanks you want to put underneath around the structure. Now make the structure lift off and then land back down. It helps to have the units hot keyed. Now when it starts to land, move the units to the exact middle of the buidling and siege mode them. Obviously some might mot be in the middle, making them still vulnerable to reavers and melee units. Un-siege the tanks that aren't in the middle, because the middle is the only place that's safe, in the 3x3 structures, and try to siege them in the middle, when they try to exit the structure since the computer will force them out.
Now this trick takes a lot of practice to pull off, and might not work on the first or even second try. Well it's not that hard, since I can always get it on the first try with 1 tank. Though placing more than 2 tanks underneath is not worth it, and takes too long for a real game.