This tool is based on the work of user Arachobia on RPG Crossing with his permission. He had taken a list of tables from Dragon magazine #422 in an article called "Building Character" by Matt Sernett and updated them for 5th edition. I've turned them into an automatic tool for generating a characters background.

Instructions: Refresh the page to generate a new background story. As always, you can use it however you like and fill in your own details. Your age and acquired proficiencies are listed at the bottom and are based on the results you got. Try to pick a Race/Class/Background combo that fulfills all the proficiencies. Your age may also result in ability score modifiers that can be applied after building your character.

...or ignore everything and do whatever you want. Whatever.
Background Generator

(T.101): If this is your 1st roll on this table you were raised by animals or beasts. They can either be unintelligent creatures like wolves, or a sentient animal like a unicorn. You will have proficiency in Animal Handling. Continue on to Table 2 and it is up to you whether any siblings you have were your biological siblings, or your animal-parents own young, or a mixture.

(T.2): Two stepsiblings, each with a different parent.

Choose one...
(T.3): Plague strikes down most of your family. You are sick as well, so roll and Table 31 to see how you fare. You choose to have started adventuring after this tragedy.
(T.3): Plague strikes down most of your family. You are sick as well, so roll and table 31 to see how you fare. You can continue your backstory by rolling on table 17.

    >>>> (T.31): You pull through easily enough. You will have proficiency in Survival.

(T.17): You were in the wrong place at the wrong time. You are sent to jail on Table 21.

(T.21): You spend a year rotting in captivity. Roll an Table 31 to see how this affects you, then roll on this table again.

    >>>> (T.31): You barely make it. The experience leaves its scars, both physical and mental, but you find ways to compensate.

(T.21): You share a cell with another: roll on Table 15 to see their crime. You both manage to orchestrate an escape: flee on Table 19.

    >>>> (T.15): Smuggling.

(T.19): You manage to shake your pursuers who appear to give up, for now. You will have proficiency in Stealth. Your life of adventure begins.


Total Rolls: 10
Your age is ADULT
Adults are at the most equalized stage of development. From here their physical body will begin to weaken while their minds and personalities benefit from experience.
Adults have no modifiers to their attributes.

Proficiencies:
Animal Handling
Survival
Stealth