The Last Gasp -- for less people?
Is there any way to modify it for only 10 players -- including the host?
My response:
The short answer is: almost certainly.
The longer answer is, um, longer.
The Last Gasp is for a minimum of 14 people. To take four roles from that will mean combining several roles - and is likely to be quite a lot of work. Whoever is doing the work won't be able to play - they can only host (because to do all that work they will have to know who the murderer is and will have to understand all the roles to be able to edit the game).
(On top of that, the game is supplied in pdf format, so it's not going to be easy to amend.)
So while it may be theoretically possible, I think it would be a lot of work and you run the risk of the game not working properly.
As I always stress, it's much better to choose a game that's already written to suit the number of guests you expect. In your case, I suggest you look at The Final Curtain instead.
Click here to learn more about The Final Curtain.
Click here to learn more about The Last Gasp.
