Just wondering if there is anyway to modifiy fog of war in game, I think I've seen this in some old maps. But I need it to be at a specific location, Not just all over the map. Like maybe a 2x2 patch of earth. Thanks.

Either you can use map revealers, or edit the Fog and make sure the player sees that area once (via an Observer that is destroyed later, etc).

Map revealers wont permanetly allow that space to be greyscale though? If you remove it will go black?

I don't understand what your saying.. I remove and create map revealers? Can somone explain please...*Nudges falkoner*

Map Revealers stay in the game until removed via triggers, are invisible, and give vision of a spot forever.
If you want it to go to gray, remove the Map Revealers at that spot.
If you want it to go back to black, not gonna happen ;p

You can also just create and remove a unit for the player very quickly, and that will give you Fog of War, the problem with using Map Revealers is that when you remove them you must remove all of them in order to do so, so you can just create and remove a unit, maybe have a small wait in there and that should give you vision of the area for a second, and once it's removed, its Fog of War will remain there.

There is no way to get precise as 2x2, although units like spidermines can get close to that, and there is no way whatsoever to make a spot completely black once it has been seen.

Okay but is there a way to speed up trail vision? Like if you created a unit then removed it fast, Vision would be there for awhile. Can you speed up that anyway... I doubt it.

Nah, there's no way to do that, is there any reason why giving them full vision for a second is a problem?

Vision gets updated every 4 seconds on fastest (based on me counting, you can test the actual amount.) but moving/creating a unit currently owned by the player gives instantaneous vision (in both the new area and the old area up until the next 4 second interval).

If you can figure out an approximation for the vision update using death counts, you might be able to get a good estimation on when you can make the unit so that the vision will be removed in a short amount of time.