My first movement as a player and becuase of the Environment card in play I have to deal with this, what does it mean?

Say for example it's this:

The first clause says that if you're making a Speed check (while in Arkham, not an Other World), you get a –1 to that check. Say it was supposed to be a Speed (-2) check and you had your Speed marker at 4. With the additional –1 from the environment, you'd be rolling 1 die for this check.

In addition, during the Movement phase, you receive one fewer movement point. So that slider of 4 Speed will get you 3 movement points while in Arkham (in an Other World, you never receive movement points).

But there is good news. To counter the penalty, sneak checks made in Arkham, which includes evade checks against namely monsters, all receive a +1 bonus. And it might relieve you to know that Fire Vampires get flushed off the board. This may or may not be a good thing in the end.

Let me also add that I find it delightfully ironic that we're teaching H.P. Lovecraft how to play the game that he himself ultimately inspired.

Although, I guess, if HPL were spontaneously alive today, that's exactly what we'd be doing

Nah, I think he hated games too

Oh god, I just sat here and typed a really detailed post with a couple of Lovecraft quotes from letters about games and then when I click post, it just took me back to the page. What on earth was that all about!

Please try again Id love to hear them, read them anyway

If you're like me, you only remember the +1/-1 mods for about three turns or so. Fiddly little things.

Yea, that happens. It's hard to keep track of everything, especially when you're playing with all expansions.