JoeGKushner said:
1. Stormbringer: There was a huge time in my younger days
Back in the late 70's, playing with high school buddies. The four of us rotated GMing and ran multiple characters each.
Stan introduced a sword like Stormbringer that Jim's fighter got his hands on. Only...after killing 100 creatures, it turned on it's owner and killed him. Irreversible death.
Jim's character gets killed by it. Jim's Wizard does some research and finds out that the sword was made by Calir, the God of Magic. Jim's Wizard gates in Calir and argues with him, demanding that his friend be returned from the dead. Calir kills the Wizard. Jim doesn't accept this - with a bit of truly highschool logic - "Well I'm a DM too and I say it doesn't happen!"
They had a big huge argument about it in their physics class.
Well....Jim was a jerk. His style of GMing was to take out every perceived slight against him on the rest of us.
Other Artifacts:
In another game a short while later, I had two opposing alignment swords which were essentially Lightsabers. Were +6 to hit and did 5d4+6 damage.
And in my last game, the Wizard found a marble. A small ball of marble stone that radiated intense magic. Now, in my setting, Wizards can automatically detect magic, to a degree. The higher your level, the weaker the magic you automatically detect. The stronger the magic, the lower level you need to be to "see" it.
Detect Magic essentially only raises your effective level for detecting magic.
The player never did figure out what the marble did. The truth is that it does nothing. It's merely a testing stone for finding those with "the power" - the potential to become Bards or Wizards - which is a genetic trait. The marble is so strongly enchanted that even untrained potentials can "see" the magic.
So you carry around the marble, play with it taverns, etc. If Joe Commoner notices that it's glowing or speaks up about feeling something from it, you know that he has the potential to be trained as a Bard or Wizard.