Instead of stress and consequences, I am going to use a set of defined conditions. Partly because I want to make the game easier to handle (no need to explain how stress boxes work, no need to think about consequences), partly because conditions are going to implicate truths about the setting (both by their description and by how you are removing them).
There will be six conditions in the game, allowing for 14 shifts of stress-soaking as recommended by the Fate System Toolkit, page 19. The conditions will follow all of the rules outlined there. You need to take a specific action (namely, drinking blood) to get rid of the two-shift consequences, and you need to initiate a specific recovery action and roll at a Great (+4) difficulty to begin recovering the four-shift condition.
The conditions are:
- Irritated (1-shift condition)
- Hungry (1-shift condition)
- Angry (2-shift condition)
- Famished (2-shift condition)
- Raging (4-shift condition)
- Ravenous (4-shift condition)
So you are progressing from irritated to angry to raging, and from hungry to famished to ravenous. This implicitly models vampires as very emotional creatures and also dependent on blood. Remember that conditions can be invoked and compelled just like other aspects, and that the first invoke is free after gaining the condition.
NPCs and conditions: It is recommended to treat nameless NPC as an obstacle with a difficulty of Average (+1), Fair (+2) or Good (+3) and not even worry about anymore details (see Fate Core, page 217). Supporting NPC should have a skill column (maybe up to two steps better than the PC), and if they are vampires they get either the irritated, angry, raging or the hungry, famished, ravenous condition track, but not both (decide what you would like to highlight about the supporting NPC: his anger or her hunger). A human supporting NPC will take conditions along the lines of bruised (1-shift condition), injured (2-shift condition) and broken (4-shift condition). Main NPC should get a complete character sheet (according to Fate Core, page 220). If they are vampires, they get both condition tracks. If they are humans, they still get only the bruised, injured, broken track to reflect that they are more fragile than vampires.
How to Gain Conditions
You gain conditions mostly as a result of conflicts,when you push your character to his or her limits. Of course, the GM is still at liberty to assign conditions as a consequence of events in the fiction (Fate System Toolkit, page 18).
When you concede a conflict, you gain one Fate point plus one Fate point for each condition suffered during the conflict, as normal.
Getting Rid of Conditions
The 1-shift conditions (irritated, hungry, bruised) vanish after you had some time to cool down. Usually it takes a scene to recover them.
The 2-shift conditions (angry, famished, injured) need a set of specific actions. A vampire's body and mind are pretty capable of healing themselves, if you have enough blood to recover. Thus, the angry and famished conditions go away, when you have time to drink blood. This can be either freshly acquired at the carotid artery, from animals or a blood bag. How to get blood will be explored later,
The injured condition can be recovered, when you get your injury attended either by first aid or at a hospital. No rolls necessary, just an in-game justification for getting well. It will still require some time to get the treatment, though.
The 4-shift conditions (raging, ravenous, broken) require more effort in order to get rid of them. A broken human probably needs treatment at a local hospital and a Great (+4) roll of someone skilled in medicine. That could either be some nameless Good (+3) doctor or a named NPC or PC with medical knowledge (probably an appropriate aspect and a roll with Greed to represent your knowledge).
To start healing the raging and ravenous conditions, a vampire has to reassert himself as an apex predator who bows to nobody. Starting the recovery process requires exsanguinating a human (an animal will not suffice), and overcoming a Great (+4) obstacle with Gluttony:
- Failure: either you aren't satisfied by one single death and need to continue, or you can start the recovery and erase the first box at a serious cost (typically, someone catches you in the act).
- A tie: you can start the recovery and erase the first box, but the body will probably turn up sometime later, leading to unpleasant news and maybe an investigation into the death. Create an appropriate aspect for the game.
- Success: you start the recovery and erase the first box.
- Success with style: you start the recovery by erasing the first box and can also immediately recover another condition (either a 1-shift or 2-shift condition is removed immediately, or you also start or complete the recovery process of the other 4-shift condition).
The second box of the 4-shift condition is removed at the end of the next game session in which the character participates.
Disclaimer: Remember that Fate is a game where people make up stories about wonderful, terrible, impossible, glorious things. It is not meant to incite you to any real-world action! Vampires are fictional.