For a spot of fun in any roleplaying campaign: Introduce the embarrassing parents of one of the PCs. After all, everyone has parents, right?

And a word of advice to players: Make sure you specify orphan on your character sheet.

(And a secret additional word of advice to GMs: An orphan is merely someone who doesn't know where their parents are at the moment.)

(Secret additional bonus advice for GMs running games where the PC manages to establish that yes, their parents really are dead: Zombie. Vampire. Lich. 'nuff said.)

Transcript

Leia: They're distracted. Let's hustle.
Luke: We should wait for Obi-Wan.
Leia: We'll wait on the ship. Come on!
GM: Luke, as you're heading across the hangar, you see Obi-Wan and a figure wearing all black, duelling with laser swords.
[SFX]: Whooom!!
[SFX]: Whooom!!
Leia: Daa-aad, stop that! You're embarrassing me!
Han: Obi-Wan is your Dad?!