Optional Characters / Extra Guests 

Optional Characters:
Each of our games employs two optional characters to allow for flexible party sizes. However, these two parts, although being non-suspects, have full partipating roles if present, rather than being entirely superficial to the game (as with some other m.m. games).
They have Introductions and Conclusions, lines in the Acting Scenes and important Questions to ask in each round, but if they are not present, their lines pass seemlessly to other indicated characters. 
We have taken great care with all of our optional characters to fully integrate them into the games, in order to avoid these players possibly feeling like non-contributing 'observers', with noticeably 'lesser roles'. 
However, we might suggest that with parties of 9-10, that hosts might like to consider taking these roles themselves in order that:
   1. they may be able to organise food and drinks more easily
   2. they are able to fill another role if a guest is suddenly unable to attend
   3. they are not required to give a non-suspect role to any of their friends/family
       if they feel a slight offence may be taken.  
However, hosts may sometimes feel that one/two of their guests would actually prefer to take a non-suspect role if they are, for example, first time players, or perhaps a little reserved, or they may be called away at some point.

Extra Guests: although our games are designed for 8-10 players, we have heard that a few extra guests have been successfully accommodated at some parties by hosts just observing (no booklet) or players 'doubling-up' (speaking alternate lines).