First session of a campaign, all level one characters in Pathfinder. I was GM.
Early in the session, there was a trapped door hidden under a rug leading to a secret room. The rogue miserably failed his check to see the trap and then opened the door. The blast dropped him to zero and the cleric brought him right back up to his feet.
So, the rogue, having learned the GM is willing to blast players with traps, goes and buys himself a wooden pole.
The players are given a quest to find a missing person (the man who owned the home with the previously mentioned trap). This mission leads to an underground occult lair connected to the sewer system. So, as they're clearing out cultist and their undead minions, the rogue checks every single door by tapping it with the pole he bought earlier.
At one point, after clearing out a previous room, he checks the door for a neighboring room by tapping on it. The people on the other side of the door reply by saying "Come in". This is the GM's subtle hint that tapping on doors with a pole makes noise that can be heard by enemies.
So, we come to room with the head person of the occult lair. He was level 2 Cleric with the Death Domain. He has spent his day torturing the guy they were looking for by channeling negative energy into him, then healing him up. He was looking for information that he thought his prisoner possessed. He had no spells and no channels remaining for the day.
He did have his one use of Death Touch.
This Death Cleric had no armor on, was sitting down and reading a book at his desk. His desk was on the other side of the room and his back was to the door. If the players had just charged in, he would be dead in the first round.
The rogue, still remembering his early trap experience, ignored the previous warning about the noise from repeatedly tapping on doors would make. He makes extra sure about this door.
It's worth noting, at this point, as a GM I roll out in the open.
The rogue is on point when he opens the door. The Death Cleric has passed his perception check to hear the noises being created on the other side of the door with flying colors. As the door opens, he is waiting at it's side and uses his surprise round to use his Death Touch. I roll 2d6 damage and come up with a 12.
Me: How many hit points do you have? Rogue: 8 Me: "Your character is dead"
The party panics. The paladin picks up his body and they all start running like the end of the world is happening. The session ended there.