The Beginning
We are going to be using this PDF character sheet. (Save a copy and edit it. You cannot edit this online)
If you use Hero Lab that's cool, (In fact, I suggest you cross-check your character with the free version. It finds things that sometimes get missed), but I need you to track your character on a PDF uploaded here in parallel so I can see it. 
Also, you are more than welcome to link to public Google Docs or other online editors for inventory, backstory, etc. I suggest you share editing rights with me: Lasivian at gmail.com (I might just add things to surprise you, heh)
Most of the races and classes in the D&D 5th Edition Players Handbook are acceptable. The following are not allowed: Dragonborn, Tiefling, Half-Orc.
Also note I am NOT allowing multiclassing. If people balk at this we will figure something out, but it just breaks too many mechanics in my opinion to "just take a level of" something
If you're dead-set on something else we can make it work, but we're going to have to find a reason that you don't LOOK that way. And while it's not required, but something "reasonably" cohesive to a party would be preferred. IE. a Half-giant vampire sociopath *might* just not be terribly workable.
We will be starting at Level 1. Those of you coming in later will start at the level of the lowest character in the group.
All Level 1 characters start with 4 rerolls (Explained in the House Rules wiki page: Here)
Ability Scores
I'm going to go with the 5th Edition "Variant: Customizing Ability Scores" option. (Also know as the "Point Buy System). You can find a calculator here: http://chicken-dinner.com/5e/5e-point-buy.html
This is done before adding or subtracting racial modifiers.
This allows everyone to design their character as they see fit. (This is sandbox after all)
I will also award one additional ability score point to a stat of MY choosing if you buy your own LEGO character miniature. (Minimum of: Legs, torso, arms, hands, head, main hand item, offhand item, headgear. And must be generally fitting the character. No bringing in a spaceman, heh.) I suggest Bricklink.com for this.
Hit Points
All classes receive hit points based on 5E normal rules.
The main reason behind not rolling ability scores or hit points is to get rid of that part of "pure randomness" from the game. I feel that events and their repercussions should be shaped and molded much more by the actions a player takes, and much less by the simple roll of the dice. Also in previous games, players would try to use their rerolls for ability scores or save them for hit die rolls. This removes that entirely. Which leaves rerolls more open to using for epic or strange imaginative actions.
IE. Thunor the Dwarf is pursued by certain death and needs to cross and Underdark lake to escape. Unable to normally swim with all his gear, and not having time to toss it all he has an idea and confers with the DM. He spends 10 rerolls in the category of "Gain one Misc minor item or effect of your choosing." and invents a possibility. "Wow! Imagine that! The water is SO salty here that Thunor actually floats in his armor!" This changes the story, allows the character to save himself in a fantastic and inventive way, and allows the DM openings to have fun with. "Wow, Thunor also will need to find fresh water to wash that salt off before everything he has is covered in rust!"
Alignments
I made a Wiki page for this on it's own: Here
Inventory, Money, and Magic
The Obsidian Portal kind of stinks for inventory. I suggest linking to a Google Sheet in your character description: https://docs.google.com/spreadsheets/
This is a good example Inventory.
You don't have to be this detailed, but the more detailed your inventory is, the better. IE. If you don't write down ahead of time that your character has a knife hidden in his boot you can't say he does after he's stripped of everything but his boots and tossed in a cell. ;)
For starting wealth use the maximum from the PHB.
If you are making a character to join in after we've started use this table for your starting wealth: Character Wealth Table
Magic items? You seriously want to start with magic items? Okay, but ONLY if you write them into your backstory, ONLY if your backstory is 4+ pages long (DMs discretion), and then ONLY if they are not overpowering. Keep it to 1500GP total, unless you have a REALLY compelling story! Also, I will give extra leeway for odd or strange magical items without clear effects. Be creative! For example, in the Elvoth backstory he was starting at level 4, and I tried to make the items "useful" in ways beyond simple combat or protection items. Also, avoid consumable magic items, they are not likely to have survived long enough to pass down.
Backstory
Backstory is critical. The more, the better. Why does your character act a certain way? Where are they from? What about their family? Etc, etc, etc.
Here is an example I made recently for another campaign: https://docs.google.com/document/d/1DXpb1mhN8fYxiYNw234KLZxUj6KnBDN3DiGcsDRePwY/edit?usp=sharing
You don't have to write a novel, but this should give you a concept of what I'm after. Also, it explained how he came into possession of the things he was carrying around and why they had value to him.
You can also use an extensive backstory (2+ pages) to add 1-2 additional skills and funds (No more than 20% additional please) to your character. I will nix anything that seems overpowering. (Again, creativity wins in the end. Think of it as your reward for giving the campaign depth.)
IMPORTANT NOTE!! - DO NOT make your backstory directly involve any "important named" living character from Greyhawk. (If you don't know who this refers to you probably have nothing to worry about.)
So, a quick background "question sheet".
- Do they have a family? Living or dead? Family of choice? Give me a name or two, where they are, what they do.
- Desires of the self. What is the character seeking "For themselves"? (Wealth, power, knowledge, etc.)
- Desires of the faith. (optional) "What does my god want of me? What do I want of my god?"
- Why Am I not safe at home someplace? Do I have a home?
- What else has happened to me to shape who I am now?
- What other traits does the character show?
Example:
Terfor the Rogue, Chaotic Good
- Yes, his father is alive and lives in Dyvers. His mother died in childbirth. He does not get along with his father who is a woodcutter. His father talked about "coming to Dyvers from the West" but does not talk much of that.
- Money. He resents having grown up poor. He feels that wealth equals power.
- He follows no god. But believes in them. Perhaps someday he might follow a path. Likes to discuss religion.
- Woodcutting with dad was boring. Stealing from the greedy merchants in Dyvers was much more profitable. Having nearly been caught he decides to leave for Greyhawk where the pickings are better and nobody knows him.
- He is missing his left index finger. It was chopped off one day when he dropped his axe by accident. His father had no money to have it healed. He preserved it in salt brine and keeps it in a small sealed jar as a reminder of what being poor has cost him.
- He has a soft spot for those that are very poor and will give them money and aid sometimes. He openly disadains those who flaunt wealth. He also intends to send some of his money home to his father, whom he still loves. He is not well-read and often says very dumb things. He wishes to become more "refined" and knows he has a long way to go. He likes the color blue, birds, and good music.
Motive
It's good to sum up your character's motives in life to one or perhaps two words. "strength", "knowledge", "silliness", etc. This will also help you drive your character in the sandbox world.
Growth
"leveling up" is not constrained to powers or ability scores. Remember to consider how your characters personality and desires might grow and change over time.
The shifty rogue might decide that something is worth defending. The barbarian might find new comfort in tailoring. A wizard might decide that an orphanage of children needs her to cheer them up every week. Etc.
This is more than "gather loot, buy shit, level up, repeat." YOU are telling this story alongside me.
Choose Your One Unique Thing
Your character’s One Unique Thing (their unique) is a special feature invented by you, the player, which sets your character apart from every other hero. It is a unique and special trait to your player, and markedly unusual. The intent is that it provides a special flavor to the campaign and can assist the GM in determining how your character can interact with characters and story in the campaign.
Your character’s unique should not provide general practical value in combat. That is not the intent. The intent is to open up story arcs and fun roleplaying opportunities.
(I will add more here as I think of it)