mac99

I've avoided looking at these puzzle threads so far - they're not good for the blood pressure. But wyrdness is right.

The host opening the door is a bit of a distraction. You're not getting any new info. Essentially you are being offered a choice of
A) one door. or
B) two doors.

True, one of the doors in option B has a goat behind it, which the host shows you, but you already knew that.

So :
1) pick a door.
2) keep this , or swap to get both other two.

I'd swap.