Character Creation for the most part is really easy. The game is a bit of meat grinder, so it's not super necessary to have a fully developed character with a background. Your level 1 character will probably have like 4 hp, and giving anything with 4 hp a backstory is a waste of time.
In fact, it might make a lot of sense for you to roll up 2-3 characters for ease of play once your first one dies.
Standard Fantasy classes and races will be joined by sci-fi and other classes as you explore the ship and find their locations.
For Classes and Races, Use Lamentations of the Flame Princess at first.
Don't worry, this has no controversial art in it.
For ability scores, you roll 3d6 in order, and then have the opportunity to swap two ability scores.
For starting items, it's assumed you are starting with basic fantasy equipment, enough to adventure with, as well as 3d6x50sp.
For historical background, the most it can give you is a +1-in-6 (for a total of 2-in-6, unless you are a specialist) to a skill with the name of that occupation. You may choose a background occupation, or roll on this list:
Former Occupation
Locksmith
Acrobat
Animal Breeder (Dogs, Owlbears, etc.)
Tinkerer
Shaman/Priest/Cleric
Warlord
Ex-noble
Disgruntled debt collector
Conman/grifter
Clown/Jester/Mime/Entertainer
Baker/Cook/Chef (Traveling, Common or Royal)
Messenger (common or for a mysterious group)
Sailor (Fisher/Trade/Military/Exploratory/etc.)
Current or disgraced knight (or apprentice)
Archeologist
Hunter/fur/bone trader
Woodsman/Lumberjack
Biologist/Student
Alchemist/Apprentice
Town watch/guard
Ex-slave
Ex-slaver
Gravekeeper/embalmer
Farmer (crops, luxury goods, fruit, tea, strange plants)
Botanist/zoologist
Grave robber/tomb raider
Historian
Archivist
Librarian
Witch hunter/apprentice/inquisitor
Healer/medical expert
Cartographer
Innkeeper/Barkeep
Carpenter/craftsman/wheel-maker
Mason/stoneworker
Thatcher/roof builder/high-up worker
Wiseman/Wisewoman
Fortune teller/Soothsayer/Augur
Mercenary
Prisoner (ex/escaped)
Beggar
Miner
Engineer/Architect
Leather worker/hide worker/chain/scalemail maker
Animal keeper/collector/trader (pets, mammals, reptiles, birds, unusual)
Artist/Painter/Carver
Assistant to a witch
Watchmaker/Clockmaker
Machinist
Witch/wizard assistant
Pirate/Ex-pirate
Astronomer
Explorer
Part of a demon/monster hunting town protectorate
Cowherd/Goatherd/Shepherd/etc.
Butcher
Gardener/groundskeep (castle, palace, etc.)
Nun/Monk
Wrestler/Boxer/Athlete
Book/scroll collector for an organization
Ex-cult member (or current)
Ex-bandit
Street magician
Author
Teacher/Professor/tutor (common and royal)
Musician
Philosopher/Thinker
Singer/performer (at pubs etc.)
Sex worker/ex-sex worker (escort, mistress, etc.)
Candle/torch/lantern maker (light maker)
Glassmaker/glassblower
Cooper (barrel-maker)
Blacksmith/Silversmith/Goldsmith/Brazier
Brewer
Barber/surgeon
Navigator (naval or land)
Armorer
Ferryman
Soldier
Warden/prison guard
Herbalist
Tax collector
Executioner
Gamekeeper (ranger)
Thief
Light battle mage
Sewer keeper/guard
Town scout/”problem-solver”
Shipbuilder
Enchanter’s apprentice
Detective/sheriff/lawman
Test subject
Fletcher/archer/bow-maker
Overseer/manager (mine, castle/fort build, etc.)
Exterminator (using traps, birds of prey, etc.)
Jeweler
Miller (flour/grain, etc.)
Stablehand
Gambler
Diplomat
For saving throws, you want to convert Death/Breath/Device/Magic/Paralysis to Fortitude/Reflex/Will. To do this, translate your Death roll directly to your get Fortitude roll. Your Reflex save is the median (rounded down) number between your Device and Breath saves. Your Will save is the median (rounded down) number between your Magic and Paralysis saves. This is, admittedly, a bit of math to translate. My bad, but you're a MW nerd, so you'll do the math and like it. <3
Cleric Class Changes
Now get a Faith pool, which is 1d6+1/level points, rolled while praying for spells, that they can use to modify any die roll in the game pertaining to them. Faith must be used after the die is cast but before the results are revealed. Faith points are restored upon prayer after a long rest.
In Game Example:
Player: I attack! *rolls* Oh got a 12, I'm going to add 3 of my 4 faith points to the attack roll cause I know a 16 hit last time.
GM: you hit. enemy rolls a save vs paralysis, passes
Player: Actually I'm going to add -1 to their roll using my last faith point.
GM: he still passes because he rolled an 18 and their death save is 12. It’s their turn, they’re going to swing at you, *rolls,* it’s a 16, that’s your AC right? Too bad you didn’t save that last Faith point.
Sometimes, if a cleric prays in specific ways or devotes specific actions or sacrifices to its god, it can increase the size of the die rolled for faith per day. Losing favor with your god can likewise decrease the size of, or remove the die roll altogether. For example, spending a day constructing a morbid chapel out of corpses for the worship of the Exclusive Baleful God of Death might grant you 1d8+level faith points when you pray to that god at it. Seeking help from other godlike entities, or growing a garden at the Exclusive Baleful God of Death’s chapel might cause you to only roll 1d4+level.