I had a DM once who prepared a large complex full of twisting passages with lots of encounters in them. We were supposed to slog through it looking for the McGuffin. I wasn't about to do this randomly and get lost, so I announced to the group that we were going to follow the "Right Hand Rule". This confused the DM, but he grew more and more agitated and we soon found the item with minimum fuss. It seems the DM had never heard of the right hand rule and the "secret" to finding the McGuffin just happened to be taking all right turns from the entrance.
For those not familiar with the right hand rule, it simply means that whenever you are presented with a choice of directions to go, you always take the one on the right. That way, when you want to leave, you always take the leftmost turn and it will lead you out. It's less subject to tampering than marking the walls or trailing a string behind you (and anyone who has read the 1e books ought to know the problem with trailing a string...)
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Another one was the character I draw my screen name from. Max Kaladin was a Paladin of Torm. Max is one of the longest lasting characters I ever had. Further, I'd rolled well for his stats and gave in to the temptation to make him "be all he could be". In other words, I min-maxed him. Among other things, he had 18/00 strength and a high constitution. He was a killing machine. We used to joke there was a panel on his armor you opened up to set him to "slice, dice or puree". This had already caused some trouble by the time of this incident.
Max was travelling with his companions when they reached an area being terrorized by a dragon. After much ado, we tracked it to its lair. That's when we found out it was a mated pair. We were supposed to turn around an go looking for help or something. I don't remember what he expected us to do. My paladin, however, was very confident in his abilities and I, as a player, knew he was a very tough paladin. My paladin was also not about to let these things go around eating people any more, so he drew his swords and calmly walked in. The DM was very surprised, but Max was prone to do things like that -- not because he was suicidal, stupid, arrogant or proud, but because he really was that good. His gift from Torm was his strength and skill and his duty was to use them to protect the innocent. He thought he could win so it was his duty to fight the dragons so they wouldn't have any further opportunity to hurt people. It was really that simple.
Anyway, the party then heard a great ruckus with lots of roaring and sound of battle. Then, there was utter silence. I wish I could say I came walking back out cleaning the blood off my swords, but I didn't. Oh, I didn't die. I killed both dragons in a massive melee while barely surviving. The problem was that the DM ruled that since I had killed the last one while it was trying to bite me, the head fell on me and pinned me down. I was still trying to work my way out from under it when the party finally worked itself up to peeking inside. That was what shocked the DM. The dragons were supposed to be too tough for us and we were supposed to go off on some long quest or something to get help but I short circuited all that.
The DM made me retire the character shortly after that. I miss Max.