Here's a somewhat more "official" version of the Gazebo story:
Eric and the Gazebo
ROLE-PLAYING GAMES SIG
by Richard Aronson
Let us cast our minds back to the early days of fantasy role-playing... In the early '70s, Ed Whitechurch ran "his game," and one of the participants was Eric Sorenson, a veritable giant of a man. This story is essentially true: I knew both Ed and Eric, and neither denies it (although Eric, for reasons that will become apparent, never repeats it). The gist of it is that Eric... well, you need a bit more about Eric. Eric comes quite close to being a computer. When he games, he methodically considers each possibility before choosing his preferred option. If given time, he will invariably pick the optimum solution. It has been known to take weeks. He is otherwise in all respects a superior gamer, and I've spent many happy hours competing with and against him, as long as he is given enough time. So... Eric was playing a neutral paladin (Why should only lawful, good religions get to have holy warriors? was the rationale) in Ed's game. He even had a holy sword, which fought well and did all those things holy swords are supposed to do, including good or evil (by random die roll). He was on some lord's lands when the following exchange occurred:
ED: You see a well-groomed garden. In the middle, on a small hill, you see a gazebo.
ERIC: A gazebo? What color is it?
ED: (Pause) It's white, Eric.
ERIC: How far away is it?
ED: About 50 yards.
ERIC: How big is it?
ED: (Pause) It's about 30 feet across, 15 feet high, with a pointed top.
ERIC: I use my sword to detect whether it's good.
ED: It's not good, Eric. It's a gazebo!
ERIC: (Pause) I call out to it.
ED: It won't answer. It's a gazebo!
ERIC: (Pause) I sheathe my sword and draw my bow and arrows. Does it respond in any way?
ED: No, Eric. It's a gazebo!
ERIC: I shoot it with my bow (rolls to hit). What happened?
ED: There is now a gazebo with an arrow sticking out of it.
ERIC: (Pause) Wasn't it wounded?
ED: Of course not, Eric! It's a gazebo!
ERIC: (Whimper) But that was a plus-three arrow!
ED: It's a gazebo, Eric, a gazebo! If you really want to try to destroy it, you could try to chop it wih an axe, I suppose, or you could try to burn it, but I don't know why anybody would even try. It's a @#%$*& gazebo!
ERIC: (Long pause - he has no axe or fire spells) I run away.
ED: (Thoroughly frustrated) It's too late. You've awakened the gazebo, and it catches you and eats you. ERIC: (Reaching for his dice) Maybe I'll roll up a fire-using mage so I can avenge my paladin...
At this point, the increasingly amused fellow party members restored a modicum of order by explaining what a gazebo is. This is solely an afterthought, of course, but Eric is doubly lucky that the gazebo was not situated on a grassy knoll.
[Reprinted from the SIG's fall '87 Spellbook #13, edited by Corey and Lori Cole, via Mensanity, Lewis Wasserman, ed. Send your compliments to the author along with your subscription to the SIG newsletter ($8) in care of L Mary H. Kelly, 4030 Valley View Lane #233, Farmers Branch, TX 75244.]
The version of this story I know has Eric attacking it, the GM occasionally rolling dice for the Gazebo attacks (which miss) and eventually Eric destroying it and asking for the experience points.