Well, I just told a story over on the house rules thread about how I killed off all of my plaers one time and I have got to say that was my biggest screw-up as gm. I was just wondering about some of the mistakes you may have made and what happened because of them.
To get things statered I will repost my tale of woe from the other thread:
I had a problem with characters in a GURPS supers game long long ago. We decided to make a god level infinity crisis, save the world scenario, and we had five 1500 point characters. All of our games were fairly combat heavy so everyone had the ability to level a city if they wanted to.
I decided to start the game with a fairly standard group of three villains, two 500 point supers and their 750 point ringleader. I wanted this to be an opening to the action; an easy victory t set the mood before the herald of doom showed up. Their only advantage this team is that I designed them to work as a team. The ring leader could fill an area with smoke that he and his teammates could see through but would make the area invisible to anyone else. There was a tank that could extend a force field to protect the rest of the team, and there was a blaster attack the supers. If you took out any one member of the team and they would all fall.
The problem was, all of my players didn’t work together as a team. No one had any powers to neutralize the smoke to they were fighting blind, and they didn't think to make any kind of plan to deal with the situation. My underpowered team of super crooks destroyed a team that should have had them for breakfast.
After that point, I didn't make the characters for the players, but I did always make the first session of any campaign for character creation where everyone designs their characters together, with gm and player input.