Hello! Prep-for-play threads are legitimate topics for this forum as long as a real game with real people is being prepared, as opposed to speculative what-ifs.
As you mentioned, I'm a big booster for The Whispering Vault, and I think it's generally misunderstood and under-appreciated. So it's cool to see people considering it ... but unfortunately, I am not encouraged by the context of play you're describing. A single session, with former gaming friends, and what's more, a lot of them ... you see, I did this back in 1992, with Champions, a game that was very influential on The Whispering Vault's later design. I wrote about it a little bit in
Your worst campaign ever? (http://www.indie-rpgs.com/forum/index.php?topic=1659.0). To follow up on my comments there, one of our biggest problems in that game (out of many) was that we all had different ideas about what was fun about our old game, and regardless of the differences, none of us had much commitment to the
new game in and of itself. And I'm not talking about game system, just the basics of characters and setting.
So I'm concerned that you may be facing some of the same issues. I could be very wrong, and you know yourself and these people, whereas I do not. I do think it might be useful to consider what you think the Social Contract is, in terms of the purposes of play. Is learning a new game part of it, i.e., do you think they really
want to learn a new game, at all? Is playing this game something that you are showcasing for them, and if so, why? Are you promising them a good time which
you are expected to deliver to them, in a totally transitive fashion? For my part, I didn't consider these issues, and now I really wish we had simply played cards or something similar during that summer.
All right, with that aside, I think you've chosen a great setting and time-period for the Hunt. I will now provide a bunch of advice which is of course entirely at your option to consider.
I suggest prepping about three human NPCs, and for the first run, keeping them and their relationships simple. Use the generic human rules for their numbers, rather than being cute and complex. Avoid complicated strife among them. Avoid any human magic, and make the shaman's role social, symbolic, and psychological rather than magical. Be sure to include the Innocent. Do your best not to make the humans annoying, stupid, or antagonistic. (That can wait for later sessions, once you get a practical understanding of the rhythm and thematic openness of a Hunt.) I offer all this advice in order to focus the session specifically on the Stalkers and the Hunt, but with enough foundation in human problems to be relevant, and to offer opportunities to tie into the characters' Keys of Humanity.
Quote1) Achieving an appropriate level of detail for the players and making sure everyone gets a chance to examine their characters. By this I mean glossing over some things (using pregenerated characters for a start) and maybe focusing on what makes the Vault unique (the Call, the Navigator, investigation, and subduing the Unbidden).
I think providing pre-generated characters may cause a lot of trouble, for this game in particular. The Whispering Vault is a character-centric, psychological game, much more about the Stalkers' individual crisis of identity than about anything else. Even for a single-Hunt story, I recommend that the players make the characters. Ideally, they should take time to do it, including a delay between preparing characters and playing them. In fact, as I recall, it was quite beneficial to leave some of the later details of character creation for the second step, for example, exactly which Servitors each one uses. Oh! And also, this is one of the few games for which I recommend that players write a brief (200 word) origin story for their characters.
Quote2) Providing the appropriate level of challenge. Should I leave the Locust as written? Should I buff the PC Stalkers, or will a Circle of 6 be able to handle the Locust (not too hard, not too easy).
This is a very interesting concern! What are your criteria for "appropriate?" That is a much subtler question than it may seem, and my following points are intended to poke at the deeper level rather than be addressed simply and superficially. That's why they may seem contradictory or partly so.
1. Six Stalkers is damned tough. Given experienced and emotionally-committed players, even beginning Stalkers would be nigh-unstoppable in a team this size, at least in a straight-up fight. But as I'm implying already, that presupposes players who understand how to work as a team and support one another during combat. If everyone just lines up and takes shots at a foe, they are collectively vastly less effective.
2. Stalkers are at their best when they've had the shit beaten out of them. For one thing, it's dramatic - damage in this game means meat has been torn or fried off of bone. For another, in mechanics terms, play becomes less about the exact skill values and more about earning and spending Karma Points. And in line with this, characters getting killed is part of the Stalker situation. The system
probably won't result in an early kill for a player-character, and later play may well bring in the valid question of not whether my character will die, but what their death might accomplish.
3. Don't concern yourself with whether they will be able to beat it. The Whispering Vault should not be played with the GM setting up a straw foe, in the classic "tough enough to last a while but it can and will be beaten" dungeon encounter. Failure should be an option, or victory which relies upon the ultimate price for one or more characters.
Best, Ron