- The campaign does not end immediately because of the betrayal.
- No players leave over the incident (a player leaving as impetus for the incident is different)
- No tears are shed.
We ran a Dragonlance 2nd Generation campaign about 2 years before the books of the genre were anounced. The lead hero was the son of Tanis and Kitara raised by lord Soth in hopes he could redeem his honor. This went along well but my friend role played the character too well. He tore the party apart because half wanted to follow him to power and glory while the other half saw where the path would take them. A battle ensued and only one player on the good survived to spread the tale.
The players whose good characters died had created new characters that fit better with the new campaign. I cant say that no tears were shed but there were no real hard feelings... Though every once in a while the fact that the knight had killed the cleric in cold blood did come up over and over when we needed to lighten the mood. The campaign continued for about 6 months until it was inevitable that Krynn would be conquered. We even had a minitures battle where they destroyed the High Clerists tower.
Then we flipped all the pc's became NPC's and we ran a new campaign with more hero's to fight the war of the Hourglass. When the books came out we decided our story was far superior... Rastilin didnt become a reformed drunk in ours.
What it did require - We stopped the game play and explained what was about to happen. If anyone was attached to their character I promised them an out. No one took it. They fought the battle knowing they would lose. The warrior that escaped did so not to survive as a character but to get the word out. The player who eventually killed that character was the original characters owner.