Please cite some examples from your experiences where the DM was taken by surprise by the actions of the characters (and left dumbfounded and temporally defeated), whether you were a player or the DM.
Back when we were playing second edition (with optional skills and powers), we had six to eight regular players in a game that spanned years. We used a rotating system of DMs, there were four of us that took turns for a moth or so at a time. One of the players decided to give it a shot as DM for the first time, and created an elaborate scenario. He placed an open call to adventurers to rescue some important person being held hostage by a dragon. He offered us a box of treasure and magic items as a reward. One of the wizards asked to see the treasure, and the DM handed him the box. The wizard immediately teleported away, leaving the rest of us laughing and the DM with a look of shock. We proceeded to trash his city, because he (the king) summoned us and wasted our time with no reward in sight. We played an evil party, and we were leveled in our teens. The DM was part of the group, he should've known what to expect.
I was DMing a 3.5E game, and I killed one of the player's characters. He was being greedy and the rest of the players were smart enough to run away from immanent death. I had another nasty encounter planned, so I decided to let the pissed off player play the monsters (Ogre Magi and Troll slaves), because he wanted revenge on the cowards who ran away and left him stranded to die. But instead when the combat started he turned on his fellow monsters, then asked to join the party afterward. It was pretty funny when it happened. My first impression was NO, but the rest of the party wanted to let him join. So sure... what the heck. It greatly increased the level of enjoyment of the game for all the players.
Back when we were playing second edition (with optional skills and powers), we had six to eight regular players in a game that spanned years. We used a rotating system of DMs, there were four of us that took turns for a moth or so at a time. One of the players decided to give it a shot as DM for the first time, and created an elaborate scenario. He placed an open call to adventurers to rescue some important person being held hostage by a dragon. He offered us a box of treasure and magic items as a reward. One of the wizards asked to see the treasure, and the DM handed him the box. The wizard immediately teleported away, leaving the rest of us laughing and the DM with a look of shock. We proceeded to trash his city, because he (the king) summoned us and wasted our time with no reward in sight. We played an evil party, and we were leveled in our teens. The DM was part of the group, he should've known what to expect.
I was DMing a 3.5E game, and I killed one of the player's characters. He was being greedy and the rest of the players were smart enough to run away from immanent death. I had another nasty encounter planned, so I decided to let the pissed off player play the monsters (Ogre Magi and Troll slaves), because he wanted revenge on the cowards who ran away and left him stranded to die. But instead when the combat started he turned on his fellow monsters, then asked to join the party afterward. It was pretty funny when it happened. My first impression was NO, but the rest of the party wanted to let him join. So sure... what the heck. It greatly increased the level of enjoyment of the game for all the players.