A while ago, one of my players was having a hard time coming up with a reason as to why someone of the occupation they rolled up would become an adventurer. I don't think its 100% necessary to come up with an in-depth backstory (although I often do) but I told them there are hundreds of reasons why someone could pursue the life of an adventurer. Here are just 100 of them off the top of my head:
I was a (roll occupation table) but then… (d100 roll twice or until it makes sense)
I got my heart broken, out traveling, seeing new things and getting new skills to find myself again. (If the person who broke your heart is still alive 50/50 chance they became an adventurer for the exact same reason.)
I joined the Corpse Collectors Guild, a little extra money and a decently good cause.
I went into a coma, by the time I woke up the world had moved on without me.
I discovered a talent for (class)
I wanted to go back to my family roots as a (class)
I Became a wanted man under the laws of my home country
I had a profound religious/spiritual experience
I was rescued by a adventurer caravan
I just kind of wandered off
I was kidnapped by a adventurer caravan
I got into a crazy amount of debt.
I was consumed by wanderlust
I decided to commit passive suicide by adventuring.
I was ostracized by my community.
I needed to make an exorbitant amount of money for a personal project.
I needed to make an exorbitant amount of money for a sick loved one.
I met my mentor.
I fell in love.
I lost it all in the divorce.
I got super lost.
I became bound into the service of some kind of higher power
I died and was resurrected
I got banished to another dimension for a while.
I got way too drunk
I needed to dodge the draft
I wanted to follow my childhood dream
I craved violence.
I was sent out as a right of passage, never came back
I was banished from my home.
Someone important to me died
I had a strange experience with a magical creature
I received a strange omen
I got bit by a vampire (no powers, just sun allergy and blood diet)
I was terribly cursed
I was subject to a miracle!
I took a psychedelic drug
I went stark raving mad!
I got bit by a werewolf
I got involved in a shady business venture
I got a brain injury which changed my personality
I spent some time in the can.
I got addicted to a drug that someone else in the caravan is addicted to or grows/makes.
My Family got turned into monsters.
I developed a fascination with ancient cultures and history.
I found out I speak a strange language
I received a strange package
I encountered a life-changing piece of art.
I woke up in a wizards lab, turns out I was a clone, my memories never having truly belonged to me…
I got conscripted into an elite training program.
I got replaced with a doppelganger, no one believed me.
I faked my own death
I woke up in a dungeon
I was physically enhanced
I developed an all consuming obsession`
I spent some time working for a military organization
I encountered a strange artifact
I was mentioned in a prophecy.
I wanted to look for a good place for my family to settle down, and make some money while I'm at it.
I pissed off a wizard
I pissed off a noble
I found a manual
I made a bet
I made a deal with someone powerful
I got Freaky Friday’d
I Found out I have a terminal illness.
I found out the world was going to end
I got enslaved, sold and escaped
I got sent to the future
I got sent to the past
I got consumed by a great ambition.
I made a friend
I had a kid with someone else in the caravan
I found out someone else in the caravan is my long-lost parent
I made a vow
I committed a wrong that I need to make right
I lived with a group of animals
I started to remember pieces of a past life
I started work as a hireling
I got a taste of incredible power and then lost it
I got teleported far away from home
I found a dungeon near home
I discovered a terrible truth
I got hope-pilled
I found out I have strange ancestry
I started pretending to be someone else
I got some good advice
I got some bad advice
I just needed an excuse to get out of the house.
I became inspired to write a book
I met someone who changed my life
My rival started adventuring
I witnessed something horrible
I witnessed something beautiful
I developed a desire to work with more exotic materials
I was the victim of a crime
I was captured and experimented on
I started adventuring on the behalf of someone who could not
I ate a magical creature
An animal stood up on its hind legs and spoke to me
Nothing, I was always both my occupation and an adventurer.
Alternatively, this could all be one character's very complicated personal history.