Tibs said:

Thx!

I was just looking at the list of spells over at Arkham Horror Wiki to see how many could conceivably be useful to cast if doing so drove you insane. Foresee (Cast and exhaust to re-roll any one skill check you just made) is giving me a serious headache.

Thomas Cartwright said:

I should take a moment to interject here that I strongly believe that the spirit of Call Ancient One is to get devoured if you go insane casting it. A legitimate argument can be made against this, but for this spell I will not concede.

Going to weigh in on this because it's an excellent question and issue that does stand to be clarified in the FAQ.

Using an Elder Sign sacrificially only makes sense for a couple of reasons. First and foremost because you only loose 1 sanity and stamina, it makes sense that you could drive yourself insane / unconscious (devoured) by using it. You can't go into a negative sanity state, you simply reach zero and are sent to the asylum. The second reason is being as Elder Sign is an item with no die rolls attached after you activate it. Comparatively speaking, there IS a die roll after you decide to pay the sanity cost on a spell. To me, this is the most important difference between casting a spell regardless of the fact you are going to go insane and using an item which will cause you to go insane.

Flute seems to make the most mechanical sense if you treat it as a combat check against a single monster who only needs 1 success to be defeated. Because of the way flute works, this happens to defeat all the monsters in the area but you can't make the check in you're insane and at the asylum. This deters investigators from voluntarily playing it when they stand to go insane or unconscious from it's use since there is no benefit unless one can make the combat check.

So on to the OP's question. In my games, I've found that the application of this rule is very very very situational. It is very easy to abuse it. Be careful with how you apply the rules and hopefully we get a FAQ that can clarify this one.

That analogy doesn't work because you're never making a combat check, even if you fully survive the use of the Flute.

You're blowing into the Flute, and it emits the sounds of the Outer Gods, which kills all the nearby monsters and brutalizes you. So whether or not you're actually sane and conscious, the monsters are still defeated.