Ok, some encounters say "may", as in you have a choice to follow the text of the encounter. Other's do not, but they seem like they should. Memory fails at the exact text, but there's an Other World encounter where you attempt to lever a gate open. If you succeede you gain 8 bucks. If you fail you lose two stamina. The text does not say may, but it seems like the type of thing you can decide to do or not. I'm thinking something like that might've been missed.
Some cards say "may", some don't but seem that they should
Perhaps the investigator doesn't realize how heavy the lid is until he actually tries to lever it.
If the encounter doesn't say "may," then it's mandatory.
Additionally, when presented with a skill check (either mandatory or following a "may" choice), you can't choose to deliberately fail the check, even if the failure is more beneficial. This applies when failing an evade/combat check against a Nightgaunt, or one of the encounters where if you pass the Lore check you lose sanity, etc. If you have dice to roll, you have to roll them.
But you can choose not to use weapons when fighting a Nightgaunt so that you get flung through the nearest gate - and if you're smart you'll probably whack your Will up to pass the Horror check and fail the fight check too.
I think it's been officially clarified that the word 'may' is the important one. It might be in one of those Ask Kev threads.
If it says "You may do such-and-such..." then you can choose not to; if it just says "Pass a such-and-such skill check..." then it's a sort of instruction; you have to make the check and live with the consequences. It's a bit counter-intuitive but that's AH for you.
I never liked the encounters were you can choose to do nothing; it seems dull and it annoys me when players in my regular group choose the 'do nothing' option. I say that if there's even a tiny chance of a reward or even just an interesting adventure, give it a go! The only exception is that haunted curtain at the Library or wherever it is - the one where you roll four dice and if they're not all successes, you're devoured. That's crazy. Obviously never do that.
(As a side note, there's also at least one encounter (can't remembr where) whcih is misprinted as "Make a Skill (-2) check or lose whatever" and it means "pass" not just "make" - you have to actually succeed at the check.)
thecorinthian said:
I say that if there's even a tiny chance of a reward or even just an interesting adventure, give it a go!
...That's crazy. Obviously never do that.
And the award for Fastest Exception to the Rule goes to... 
Seriously, buddy, intentional or not, that just hit me as the funniest thing this morning.
There are some encounters that really grate my nerves about this sort of thing.
"Overdue book fines of $4. Pay up or move to the street!
There's nothing in that encounter that indicates that you have to pay your fines. This was pointed out by a friend, who was rich at the time, who immediately moved to the street. This encounter is pretty much just that.
There's an Other World encounter that indicates you have to escape from a sleeping horror, but it says may. Sneak checks are the most difficult to prepare for in another world, so that's a godsend. But why give it that flavor if you don't have to do it?
flamethrower49 said:
There's an Other World encounter that indicates you have to escape from a sleeping horror, but it says may. Sneak checks are the most difficult to prepare for in another world, so that's a godsend. But why give it that flavor if you don't have to do it?
I think in that encounter, you're trying to steal something from it. I can see why the choice is there. Usually, I don't attempt the check unless my sneak is reasonably high.
jgt7771 said:
thecorinthian said:
I say that if there's even a tiny chance of a reward or even just an interesting adventure, give it a go!
...That's crazy. Obviously never do that.
And the award for Fastest Exception to the Rule goes to...
Seriously, buddy, intentional or not, that just hit me as the funniest thing this morning.
Heh heh, it was meant to be a joke. I suppose it is a question of where you draw the line, but I'm a rank coward when it comes to that twitching curtain. The chances of success are about 0.11, and I don't like them odds, no sir...
I don't see what's so odd about having the choice between paying library fines and moving to the street, though. They tell you that you have to pay a fine; your response is to just run out of the building as fast as you can. Seems like a plan to me. The average life expectancy of Miskatonic librarians is probably about three days, so you can just wait until the current librarian is dead (eaten by that big blue thing that's chasing Daisy Walker, or whatever) then check out more books under a false name. It's 1926! What are they going to do? Google you? I don't think so!
Tibs said:
I think in that encounter, you're trying to steal something from it. I can see why the choice is there. Usually, I don't attempt the check unless my sneak is reasonably high.
Well, there's another one that doesn't give you a choice in terms of stealing something from it. It's only for $3, and I wouldn't do it most of the time. But for this other encounter, you have to. I just think the consistency with which they use "may" or "if" is sometimes a little off.
Then I guess it's up to the person who is reading the encounter to spin a tale that makes the situation plausible.
"I have to steal that crystal key from its guardian in order to open the vault door and escape! Once I'm back in Arkham though, it'll do me little more than to pawn off for a couple of bucks."
Wat I see it if they didn't force you into encounters most people would refuse to do them. Generally speaking, reaching into some strange plant or reading screaming books is a bad idea and if the cost outweighs the reward it'll be seen as a deterant to winning. Want to win? Don't take risks. But taking most of the choice away from the player makes it that much more satisfying when you pass and let's you point out it wasn't your fault even if you wanted to take the encounter anyway. Plus it adds to theme of having little control over the situation and isn't that what HPL is all about?
Gatha said:
Wat I see it if they didn't force you into encounters most people would refuse to do them. Generally speaking, reaching into some strange plant or reading screaming books is a bad idea and if the cost outweighs the reward it'll be seen as a deterant to winning. Want to win? Don't take risks. But taking most of the choice away from the player makes it that much more satisfying when you pass and let's you point out it wasn't your fault even if you wanted to take the encounter anyway. Plus it adds to theme of having little control over the situation and isn't that what HPL is all about?
Really! I see the opposite. Most players are disappointed when they don't have an encounter. Even though I tell them its 2:1 against them having a benefit. (About 1/3rd are neutral). Some places are better and worse than this.
The "may" encounters tend to be dangerous with big payoffs, IIRC. Otherwise I'm happy with forced encounters. What I don't like straight out penalties with no chance of rolling.
There is one player in my group that hates the bad encounters more than anyone else I know and probably takes the safe route whenever he can. More often than not however, he is forced to "take it like a man". But the (very!) few times he makes it out of a horrible encounter in an other world, he is also the player to cheer the loudest 
Arkham horror is probably the only game where I welcome tons of crap being thrown in the players general direction. It makes those few bright moments all the better 