Creating a Zero-level Character in D&D 5E

Zero-level characters are just that, the ZEROES of the world. They are the Inn
Keepers and Bar Wenches, the owner of the general store and the sailors manning the ships at sea. Most of these people never earn the 300 experience points needed to obtain 1st level and become one of the truly remarkable people in the world. This system is primarily for building NPC's like Torch Bearers or Scroll Caddies. However, it can also be a challenging way for player characters to start their careers. 

Ability Scores:
Players have 12 points to spend on ability scores, per the Players Handbook, page 13. You may also choose to use the Zero-level character standard array (12, 10, 10, 10, 10, 8)

Race:
The player chooses one of the races from any book sanctioned by the Dungeon Master. Modify abilities accordingly.

Alignment:
All Zero-level characters are neutral. The player will choose an alignment when the character reaches 1^st level.

Hit Points:
Zero-level characters have 6 hit points plus Constitution modifier.

Background:
The player may choose a background for his character from any book sanctioned by the Dungeon Master.

Weapon Proficiency:
All Zero-level characters are proficient in a single Simple Weapon.

Equipment:
A Zero-level character begins play with the weapon they are proficient with, a set of common clothing and a pouch with 10 gold pieces to purchase additional equipment prior to play.

Experience Points:
Zero-level characters begin play with -300 experience points.

During play: 

PC's will be given the chance to learn to use weapons, cast spells and pickup skills, prior to becoming 1st level. These abilities will be retained after they become 1st level, but cannot be improved up unless the player chooses the appropriate class. 

Weapon Proficiency: 

Any character may attempt to learn to use any specific weapon by using it in two fights and then making DC 12 Intelligence roll, on a success, the player becomes proficient with that weapon. If the roll is failed, the character may make the roll again after another fight in which they use the weapon. Only one weapon proficiency can be learned in this fashion. 

Spells:

Any character may attempt to learn a Cantrip by attempting to and successfully casting the spell two consecutive times. The character must spend 1 hour studying the spell from a spellbook or scroll. After studying the Cantrip, he may attempt to cast the Cantrip by making a DC 12 attribute roll against the controlling attribute of the spell, ie Wizard spells use Intelligence, Cleric spells use Wisdom, Sorcerer spells use Charisma, etc. Warlock spells may not be learned in this fashion, as they are pact gifts. Upon two consecutive successful castings in this fashion, the character has learned the spell and may now use it, using the normal Cantrip rules. If the roll is failed, the character must further study the the Cantrip for 1 hour and then can attempt to cast the Cantrip again. Only one Cantrip can be learned in this fashion.

Skills:

Zero-level characters roll at Disadvantage when attempting any skill they are not proficient with. Any Character may attempt to learn a skill they do not have a proficiency with. To gain a Proficiency, the character must attempt to use the skill on two separate occasions where the the skill is appropriate to the situation. Upon succeeding at two consecutive attempts to use the skill where the DC was 12 or higher, the character no longer rolls at Disadvantage when attempting to use that skill. After two more consecutive attempts at using the skill where the DC was 12 or higher, the character gains proficiency in that skill. Only one skill may be learned in this fashion.

 

1st Level:
Once a Zero-level character earns 300 experience points, putting them at zero total experience points, they advance to 1st level, the player has an additional 15 points to increase the characters ability scores, chooses a class and assign an alignment. The player may also choose a Feat as a bonus for going through the process of being a Zero-level Character.