At the beginning of the level 5a in the Terran campaign, you are assaulted with nuked ghosts. Is it possible to avoid mass destruction of the initial reinforcements by the nuclear strike, without using cheats?
Place mines in the right places!
See this video of a speedrun of the level by soulhunger1 for the exact locations:
From the video description:
I discovered that it's possible to save most of your troops by killing off some of the ghosts with Vultures. The first Spider Mine that I place is in a very specific location. If you place it in this exact spot, it will kill 3 ghosts every time. The second spider mine of the second vulture kills off 2, and all others are single kills. In total, 9 ghosts dead with 6 spider mines.