When the PCs are facing multiple sources of Fear at the same time, or shortly thereafter, how many Fear Tests should they make? The results of a failed Fear Test can be very serious indeed, considering they're probably about to enter combat, so this can be a very key question...and the devil tends to be in the details.

1) First question is, if they're confronted with multiple sources of Fear at the same time , how should it be handled?

PCs enter a room with three different sources of Fear - and they're not all the same type (one sources is a creature and one's a dark ritual, for example). Just one roll or multiple? If just one roll, do you use only the Willpower modifier for the toughest Fear rating they're facing to cover all the Fear sources - or do you come up with a Willpower modifier that takes into account all of the multiple Fear sources they're facing?

2) To what extent, if any, do the PCs become inured to a source of Fear?

Having made a Fear Test in Room#1, what would cause a Fear Test in Room #2 shortly thereafter? Ergo, if they made a Fear Test due to a creature with a Fear rating in the last room they were in three minutes ago, do they make another Fear Test in the next room because of an identical creature? Would a completely different kind of creature trigger another Fear Test in Room#2? Should a second Fear Test require a completely different kind of Fear source (creature in one room and a warp portal in the next)?

What if the creatures are daemons (thinking this might prompt a different answer with some)? Does essentially the same daemon in Room#2 trigger another Fear Test? Does a different daemon in Room#2 trigger another Fear Test?

If you think that an identical creature should not trigger a Fear Test in Room#2, - how much time needs to pass before that kind of creature necessitates a Fear Test? 5 minutes, an hour, a day...never?

Thanks for everyone's thoughts.

1) I would probably only have them take one test based on the most severe penalty/the most severe that would apply to any particular character(I say this because a Jaded character would ignore a fear 4 alien while the rest of the party wouldn't but may still have to test for a fear 2 daemon in the room, so you'll still need to keep track of the different fear sources). It would seem real dumb for a character to luck out and pass the fear test against say a daemonhost only to then immediately fail to a fear 1 zombie or something. The scariest thing should draw their attention is essentially how I would justify it.
I'm not a huge fan of the fear rules so personally wouldn't make it harder than the base fear rating makes it but doing so I think would make more sense than multiple tests. As it is fear tests are some of the hardest in the game as they get so few bonuses and so many penalties and their effects largely aren't fun for players since they take away their control of their character's and remove them from the action. Might give extra insanity and/or corruption for a failure though.

2) In room 2 I would say a fear test would be needed for anything different from what was in room 1. For an identical creature definitely not. A completely different creature definitely yes. A horror in room 1 and horror in room two would just be a fear test in room 1, a horror in room 1 and plaguebearer in room 2 would probably be two fear tests. Same with crazy warp phenomenon type events. If the first room they go into has the rules of reality thrown out the window whether they pass or fail there pretty much indicates how they feel about the continued horribleness in the rest of the warp tainted building.

You should base it off if the sources are observed close enough to be considered part of the same encounter/scene. Any particular source should only trigger a fear test once per encounter/scene no matter how many times that source is observed or duplicated.

For the former, I'd suggest having it be the highest relevant Fear rating, with a penalty to the PCs' rolls equal to -5 X the number of other Applicable Fear tests. Or, just raise the Fear Rating to compensate. A bunch of mutated cultists summoning a daemon with diabolical acts could be a Fear (2) with a -10 penalty, whereas a unit of the same kind of Daemon could upgrade to Fear (3) or higher.

For the latter, I'm not so sure. In regards to new sources of Fear, I'd totally have more tests for them. For the same kind of source a few minutes after... I'd probably have them make the Willpower roll with a bonus, a chance for their previous exposure to have inured them to such things temporarily. That way they aren't just getting a free pass, and a horrible roll is always possible... But they aren't just being hammered incessantly.