Discuss tone and content
Talk to your group about tone: Stonetop takes itself seriously, grounding itself in human concerns. The PCs are exceptional, but they aren't super-human. Violence has consequences. Monsters are scary. Magic is strange and dangerous. People matter.
The setting, playbooks, and rules go a long way towards establishing a consistent tone, but you and your players ultimately determine the game's tone in play. Obviously, you can play the game however you want. You'll almost certainly have moments of levity and silliness—you're doing this for fun, after all—but Stonetop works best when everyone mostly plays it straight.
Next, discuss any content that you and your players actively want to exclude, veil, or handle in a particular way. Explain why this is important, reading or paraphrasing the following:
"This game is collaborative, with each of us contributing to the game's fiction. We each have our own tastes, sensibilities, and boundaries, which the others can't fully anticipate. So, before we start play, we're going to establish guidelines for the content that we'll include in the game. The goal is to make the game enjoyable, comfortable, safe, and welcoming for everyone, and that's more important than anyone's sense of realism or historical accuracy."
If someone strongly objects to establishing content guidelines, or refuses to respect the wishes, boundaries, and dignity of their fellow human beings, then consider whether you really want to spend hours and hours playing with them.
Grab the Stonetop steading playbook and find the section on Content. Explain the difference between excluded content and veiled content.
Excluded content just won't be in the game, period. For example, if "torture" is excluded, then PCs won't torture anyone; monsters and NPCs won't torture anyone; no one will threaten anyone with torture; no one will have torture as part of their backstory. No torture, not even off-camera.
Veiled content can be part of the game, but only off-camera. If "torture" is veiled, then PCs, NPCs, and monsters can all threaten to torture each other, or have been tortured in the past. PCs, NPCs, and monsters can commit torture, too, but if they do, you "fade to black" or "pan away" and the actual torture happens off-camera. You can—and probably should—address the aftermath of the torture on-camera, but skip the torture itself.
Excluded or veiled content can be broad ("slavery") or specific ("graphic depictions of harm to eyes"). It can be potentially upsetting ("torture"), or something that a player finds distasteful or mood-breaking ("punny names"), or even trivial ("NPCs named 'Sean'").
Start by sharing the content that you (the GM) want to exclude or veil, plus any such content that was shared with you in advance. Then give the players a few minutes to consider what (else) they want to exclude or veil. Ask for them to share, and note the content on the steading playbook.
If you suspect that some players will be shy about sharing, have the whole group submit their excluded/veiled content anonymously (via an online document or form, note cards, etc.).
Anyone can call for content to be excluded or veiled. If one player wants to exclude something that another player wants to veil, then that content is excluded.
It's fine to ask each other for clarification on what exactly is being excluded or veiled, but don't ask for reasons. Players can volunteer their reasons, but sometimes those reasons are private, unpleasant, or even traumatic and no one should be asked to unpack that for a game.
Let everyone know that they can call for new content to be excluded or veiled at any time, in this session, between sessions, or during future sessions. They don't need to speak now or forever hold their peace.
Finally, ask if anyone has special requests regarding specific content. Is there certain content that anyone wants to handle in a particular way? Are there any truths they want to assert about the world, the village, or the game? For example:
- "Spiders are okay, but I need us to avoid describing their legs.'"
- "I'm cool with bigotry between the Hillfolk and Gordin's Delve, but I want Stonetop to be an open-minded and welcoming place."
- "I don't want the Stone to be some source of ancient evil."
- "I want to play a woman Marshal, defying a woman's 'proper place!'"
- "Let's say that gender norms in Stone top are super fluid and accepting."
Discuss, negotiate, and compromise as needed, trying to find common ground that works for everyone, and note these special requests in the steading playbook.