Strange Blades bug in Adytum
This contains some Fallout 1 spoilers so don't read it if you haven't finished Fallout 1.
After talking to Zimmerman, taking the quest, talking to Razor, talking to Gabriel, killing the deathclaws, talking to Gabriel again and talking to Razor again, I went down to Adytum to let Zimmerman examine the holodisc Razor gave me. I saved the game before talking to him.
Well, he got mad at the Regulators, they offed him, and a fight began with some Blades apparently firing from the north (I saw lasers hitting Regulators outside the window). Just then some friends showed up at my door for some boardgaming, so I exited the game without saving.
Later I ran the game again, loaded the save at the point right before I talk to Zimmerman, and again hand him the holodisc. He got mad, the Regulators killed him, the fight broke out....but no Blades. I tried this several times, sometimes the Regulator would miss Zimmerman but he would fall down anyway, sometimes they would hit him for 250 damage and he would fall down but it didn't say he died although he was a corpse that could be looted, and other minor bugginess, but the Blades would never show up.
The only thing I did differently between the first time (where the Blades showed up) and the others was run the game and load a saved game before talking to Zimmerman. Apparently once I had saved and quit, something happened along the lines of the "talk to Zimmerman without the disc" bug, because in my experiments to figure out why the Blades weren't coming I went back to the Blades instead of handing him the disc, and Razor was dead (although her standing lower torso was still there, very weird looking). I tried talking to Gabriel and he said there was no reason to leave now that the Blades had taken care of the Regulators. I went back to Adytum and the Regulators were alive and well.
This is the first time I can recall where the game behaved differently in a given situation after quitting from it, running it and loading a saved game.