SirRockNRolla says:
Being a new person to dnd in general and bringing in something that's not in, if everyone can agree on a way for non-class to work then I'd happily do any that works
Let me give it a stab then. The easiest way to do it without upsetting overall balance is to replace
just the advancement system. So what I propose is meant to be an alternative to XP gain and levelling up. All other aspects of the game will remain the same. Here's what I've got to start with:
Level 0 Commoner
You do everything you normally do at character creation, except you do not choose a class (assign attributes, pick a background, pick a race - gain all bonuses of the background and race you chose). Instead, you gain the follow benefits as a level 0 commoner:
1. Unless you gain a Feat from your starting race, gain 1 Feat
2. Gain proficiency with Padded Armor (also gain Padded Armor)
3. Gain proficiency with one simple weapon (also gain that weapon, if it requires ammunition gain 10 pieces of ammo)
4. You have a +1 Proficiency Bonus
6. Your starting hit points are 6 + Con Modifier
7. You have 0 hit dice
Skill Based Advancement
This system can replace XP gain by extending the rules to cover class advancement more generally. For now, I just describe it with respect to the advancement from a level 0 Commoner onto and to the first level of a Class path.
To advance along a Class path you must spend 5 Advancement Points associated with skills that the chosen class specialized in. Advancement Points are earned when you make skill checks, and also when you survive battles.
Whenever you make a skill check, if you succeed gain 1 Advancement Point in that skill. If you fail, gain 2 Advancement Points in that skill. Additionally, whenever you win or survive a combat encounter, you gain 1 Advancement point if it was classified as Easy, 3 if it was classified as Hard and 5 if it was classified as Deadly. Point earned from Combat are not tied any skill, and may be spent as if they were associated with any skill.
To advance along a Class Path, during a Long Rest you spend Advancement Points. Only points associated with skills on a Class skill list (those that members of that class can choose to be Proficient in) can be spent to advance along that Class path. Once you start on a class path, you cannot advance along another path until you complete the level on the class path you have started. You complete a level when you have obtained all features of that level (then you become "level 1" in that class).
If you are a level 0 Commoner, in your first Advancement you gain a Hit Die from that class and the class skill proficiencies. You also increase your maximum hit points by the value of the hit die minus 6. So if you gain a d8 hit die, you also gain 2 hit points (8 less 6). Your second advancement grants you the rest of the Proficiencies from the class (Armor, Weapons, Tools, Saving Throws). Each Advancement after the second grants you 1 level 1 Class feature. Once you have obtained all Features of level 1, you become "level 1" in that class. Your proficiency bonus raises to 2. At this point you can start using the standard advancement rules, or see the next section for details on how to use this system beyond obtaining level 1.
Your GM should, as you advance, ensure that you acquire the equipment listed in your path's starting equipment. The bulk of this should be obtained before, or immediately after, your second Advancement.
Example: Advancing to Barbarian 1
Jack Rager is a level 0 Commoner. After playing for a while, he has earned 3 points from Combat 5 Points in Athletics, 2 Points in Stealth, and 2 Points in Perception. Jack's player decides to become a Barbarian, and during his next long rest Advances. The Barbarian's class skills are Animal Handling, Athletics, Intimidation, Nature, Perception and Survival. All of hits points, except Stealth, could be used to Advance along the Barbarian Path. So, he spends his 5 points from Athletics for the first Advancement - starting on the path of Barbarian 1 - and his 3 Combat and 2 Perception points for a second Advancement.
The first Advancement grants a d12 hit die, so he gains 6 additional hit points. It also grants the Barbarian skill proficiencies and the Barbarian gets to pick two from its list. He picks Athletics and Perception as his two skills, after all those are the skills he's been using so he feels that it makes the most sense.
The second Advancement grants him the Armor, Weapon, Tool and Saving Throw proficiencies. He looks forward to the opportunity to acquire some medium armour, now that he can wear it, and a shield. A martial weapon, like a longsword, would be a nice upgrade from his dagger. Hopefully he will soon be able to buy, or otherwise acquire these now that he is proficient.
Later on he has earned some more Advancement points, 3 more from Combat (another battle), 4 in Perception and 3 in Intimidation. During his next long rest he spends all 10 points to buy the last two Advancements. For the first he gains the Rage feature and for the second the Unarmored Defense. Now has has all features of a level 1 Barbarian and so becomes a level 1 Barbarian! His proficiency bonus increases to 2 and he's finally finished the Barbarian 1 path.