All right, so Geist 2e krewe rules and mechanics, I will use an Exalted style ancestor cult (~) as an example later on. I believe that this structure can be used for non-ghost related organizations, but I'm going to use the ancestor cult to hew as close to the proper process as possible so that I don't have to homebrew anything on the fly.
What is a Krewe?
A krewe is, in essence, a group of individuals who have come together to piece together and develop their understanding of death and the afterlife, united by common beliefs and/or goals. It is a cult and religion, even if none of the members recognize it as such. A krewe made up of hyper-rational atheist scientists would still have rituals within their experiments and investigations, gospels made up of their publish theses. A krewe has understanding, it has belief, and from the mixture of those two resources, it has power.
I could probably wax on a bit more, and probably will later, but thats the gist of it.
Krewe "Character Generation"
The Cast
The first step of Krewe Creation is to create some characters, these being the PCs and a handful of important NPCs.
Sin Eaters The PCs
Make your dudes. Its assumed that the PCs will be the leaders of the krewe, but its not required. Then you are supposed to do Session Zero stuff, introducing your characters to each other, brainstorming some connection between them, why these people came together to found a death cult in the first place, etc.
The Dead
Now you go around the table and have everyone come up with an idea for at least one ghostly "celebrant," as members of a krewe are called. This is a group where life and death meet, so you need to have celebrants from both sides. You generally stat out your ghosts and give them powers, and then repeat the Session Zeroesque process.
The Living
Repeat the round robin chargen thing you did with the ghosts to create living celebrants. They get a name, a concept, and an Aspiration, to set them apart from the faceless masses. Living celebrants then get three actions that support their concept, general tasks that they're good at. These actions get 5/4/3 dice respectively, and any other actions they take unaided get 2 dice.
Background Players
The rest of the faceless masses that make up a krewe that you still want to give some detail to; if part of a PC's gang came with them when they founded/joined the krewe, for example. It is recommended that you give these groups an iconic character to be their face for when you want to interact with them.
Actual Chargen
Krewe Archetypes
Krewes get Archetypes, which honestly aren't really relevant in the long run, since all they do is provide some thematic grounding and define which Ceremonies your krewe starts off knowing. I admit, I sort of skimmed over their lengthy descriptions.
The PC archetypes are:
Furies, who are judges and vigilantes for the dead. They start with the Ishtar's Perfume, Skeleton Key, and Black Cat's Crossing Ceremonies.
Mourners, who seek out the lost and forgetten dead and preserve the knowledge and traditions they have to pass on. They start with The Diviner's Jawbone, Gifts of Persephone, and Bloody Codex Ceremonies.
Necropolitans, the socialable party archetype. They start with The Lover's Telephone, Crow Girl Kiss, and Dumb Supper Ceremonies.
Pilgrams, who explore and study the Underworld and sometimes act as guides through it. They start with the Dead Man's Camera, Gifts of Persephone, and Bloody Codex Ceremonies.
Undertakers deal with death and dead related problems. They start with the Go With Love, Crow Girl Kiss, and Death Watch, the first of which doesn't appear to exist and the last is a 1-dot Ceremony instead of 3-dot
The Antagonist archetypes are:
Elysians, people who feel entitled to having dodged death. They start with the Ishtar's Perfume, Ghost Trap, and Black Cat's Crossing Ceremonies.
Bonepickers, who are basically the Guildman archetype. They start with the Dead Man's Camera, Ghost Trap, and Bloody Codex Ceremonies.
Thanatologists, the guys who want to science death. They start with The Diviner's Jawbone, Skeleton Key, and Bloody Codex Ceremonies.
Gatekeepers, who work to maintain the current status quo. They start with the Death Watch, Ghost Trap, and Crow Girl Kiss, which is supposed to be a 2-dot Ceremony and not 3-dot.
Doctrines
Krewes start with 3 Doctrines, which are the core tenets of a krewe, the pillars of its faith. They are powerful but restricting, the source of the krewe's growth and unity, but violating them has consequences. For each one the krewe has lived by or advanced during a session, it gains a Krewe Beat. If a Krewe Action or one of the krewe's leaders openly breaks one of its Doctrines, it gains the Shaken Faith Condition, which limits the restorative effects of abiding by Creed and Virtue, and if enough time goes by without it being resolved, turns into the Coup de Etat Condition, which is exactly what it sounds like.
Virtue and Vice/Virtue and Creed
This part is a bit odd, because chargen uses Virtue and Vice, while the mechanics section has Virtue and Creed. I will be assuming the latter is correct. If Doctrines are the religious and dogmatic pillars of the krewe's faith, then Virtue and Creed are the spiritual pillars. Creed is the easy, surface level devotion and affirmation of the krewe's values, while Virtue is the deep commitment and self-reflection that helps you become a better person. When a krewe fulfills its Creed, all participating celebrants regain 1 Willpower or Plasm/Essence, and if it fulfills its Virtue, the celebrants regain all Willpower or Plasm/Essence.
Attributes
Krewes have simplified Power, Finesse, and Resistance traits, much like CoD spirits. They start with one dot in each, and have six more dots to distribute between them. Power is the krewe's ability to do things by itself, or induce change through direct action. Finesse is the krewe's soft power. Resistance represents its celebrant's loyalty and dedication to the cause. Dice pools are generally formed by Attribute + Esotery.
Merits
Krewes get 7 dots of Merits, which must have the Krewe or Krewe Only tag, and all krewes have one free dot of the Safe Place Merit, representing their place of worship.
Using a Merit is not a Krewe Action, and is not bound to the constraints that those are. Krewe Merits represent the collective capability of the krewe, not a general statement about it. A krewe with high Resources wouldn't mean that all of its members are wealthy, it could just mean that they are capable of paying regular due that add up to a decent war chest, or have a single wealthy member who bankrolls the entire group.
At this time you are to design a unique Mystery Cult Initiation Merit for your krewe, which you can assume most celebrants have at least one dot of. A Mystery Cult can be any esoteric society, from a frat house to an actual Sin-Eater led krewe, and depending on the cult different dot ratings can mean different things in-universe. For example, in said frat even the leaders might only have two dots, at best.
With each dot in MCI, you gain another advantage. 1 dot gets you a Specialty or a 1 dot Merit. 2 dots gets you a 1-dot Merit. 3 dots gets you a Skill dot or a 2-dot, often supernatural, Merit. 4 dots in MCI gives you a 3-dot, often supernatural, Merit. 5 dots gives you either a 3-dot Merit or another major advantage not represented in game traits.
Ceremonies
Krewes start with a 1-dot, 2-dot, and 3-dot Ceremony as determined by their archetype, and the Bestow Regalia Ceremony.
Ceremonies aren't just thing krewes can have, they can be learned and used by individuals just fine. The difference and advantage of krewe Ceremonies is that all celebrants know all the Ceremonies their krewe has with a rating equal to or less than the celebrant's Mystery Cult Initiation rating. Thus, krewe Ceremonies sort of represent a group power, a collective of knowledge and ability that the celebrants can tap into with MCI. They make the krewe something a little bit more than just a collection of individuals moving in the same direction.
On a related note, Regalia are basically a thing that has taken significant trappings of the krewe's mythology of how the afterlife should be. By ritualistically bestowing the Regalia upon one of the krewe's members, they become a focus of the group's faith and mythology and are thus empowered, gaining a particular Regalia Effect. This can grant effects ranging from getting 8-again on a particular Skill, increasing Rank by 1 for spirits and Sin-Eaters, or gaining access to a Key. A Krewe can only have one of each Regalia Effect, and a character can only have one Regalia at a time.
Advantages
Krewes have Esotery, the krewe Power stat, representing how well the krewe's religious tenets convey mystical understanding of the Underworld and the cycle of life and death. Esotery determines the number of simultaneous Krewe Actions the krewe can undertake without backlash, the maximum number of Tasks that can make up a Krewe Action, the Attribute Maximum, and the number of Regalia a krewe can possess.
They also have Congregation (basically the health track), which is 5 + Resistance. Losing Congregation can represent either celebrants dying, or losing faith and breaking away from the krewe.
When a Krewe takes damage, it represents either the deaths of its celebrants or members abandoning the krewe as they lose faith in its goals and leadership. Once a krewe's Congregation track is filled with Lethal damage, it enter into a period of schism, where the krewe's core ideologies are threatened and/or its leadership is contested.
A schism can be mitigated in three ways:
Purge, where the leadership uses force to silence dissent, clearing the Congregation track of damage at the cost of a Power dot.
Resolve, where the leadership and the dissenters achieve a resolution, clearing the Congregation track at the cost of a Finesse dot
Splinter, where the leadership allow the dissenters to go their own way, clearing the Congregation track at the cost of a Resistance dot.
Experience Cost
Krewes get Krewe Beats that turn into Krewe Experience, like everything in the CoD. Attributes are 6/dot, Merits 1/dot, additional Ceremonies 2/dot, and increasing Esotery is 5/dot.
Krewe Actions
The core of a Krewe Action is to generate Effort. Krewe Actions can span geographical space and time, and are always long-term projects. Essentially, they're a special kind of Extended Action. They are not supposed to occur "off-screen," and should show the crew's interconnectedness to the PCs, as well as to the world around them.
Step 1: Determine the Desired Outcome
Pretty straightforward, decide what it is you're trying to do.
Step 2: Determine Complexity
Determined by the GM, Complexity is part how long a task is expected to take and part how many steps are expected to be involved. Simple, straightforward actions might only take a couple scenes and only have a handful of steps to complete, and thus have low Complexity. Grander scale Actions might take multiple Sessions to complete.
Step 3: Determine the Tasks
Each Krewe Action is made up of a series of Tasks; the players must define a number of Tasks equal to the Complexity of the Krewe action. You may need to divide up a goal over several smaller Krewe Actions if a single Action's Complexity exceeds the krewe's Task Limit.
Step 4: Establish the Structure
Now that you have the steps that must be taken, you translate those steps into mechanical actions, and decide what order the Tasks must be accomplished in, if necessary.
Structure
For each Task, decide:
Action: simple or contested
Time Required: how long a Task takes to complete, but should usually be at least an hour.
Task Order: decide which Tasks, if any, must be done first
Dice Pool: Usually Krewe Attribute + Esotery, but if a PC or major NPC is undertaking the Task, they can use their dice pool instead.
Step 5: Generate Effort
The meat of a Krewe Action. Successful Tasks generate 1 Effort, and Exceptional Successes generate 2 Effort along with a beneficial Condition. Failed Tasks do not generate Effort, and the Storyteller applies a Complication immediately. If a failed Task was a prerequisite for later Tasks, those Tasks take a -2 penalty. If a Task suffers a Dramatic Failure, then the krewe suffers a negative Condition, and if the Task was a prerequisite, then the krewe's Task Limit for the action is reduced by 1 and the celebrants look for alternate Tasks.
Effort is exclusive to the Action that generated it, and can be used to complete the Action, spent at one for one on dots of temporary Social Merits that last a chapter, usually Retainer or Staff to represent calling in experts in relevant fields.
Step 6: Repeat
Repeat the process for the other Tasks in the Action. If a Task seems particularly interesting, then players should feel free to "zoom in" on it and resolve the Task using normal rules, and the GM determines whether the PC's performance counts as a success or not.
Step 7: Resolve Action
Once the krewe has resolved all of its Tasks, the Krewe Action is complete. Krewe Actions always succeed unless they are abandoned, so this step is about determining the cost of the final outcome to the krewe. If the Krewe accumulated Effort equal to the Action's Complexity, then the krewe was successful in their efforts and suffer no further complications. For every point of Effort the krewe was short, the GM adds a complication, which can range from the krewe taking damage to undergoing a schism.
A/N: So this isn't as complete as I'd like, but its complete enough to get across all the most important information, and I felt myself spiraling downwards into a neverending spiral of minutae. I'll start working on the example krewe tomorrow.