The question:
EDIT 2 (for more clarity):
I'll happily award the answer to the person who answers the following question with the most sincere and considered response:
Are there any major faux pas one should avoid when joining an existing RP game?
Bonus marks will be awarded for anyone who provides some helpful advice, or useful personal insight, for new table-top RPers, whilst still answering the above-mentioned question.
If you wish to continue reading, there is some unnecessary background information about this question below
Background
I've just been invited into a Rune Quest (possibly Rune Quest 2) game with a friend and some of his mates. I joined their game (which is a number of years old and still going strong) having never played a table-top RPG before. I think I'm picking up the game system pretty well.
So far (in the last month or so) we've not really moved from a particular stretch of a road, which seems to be a major highway for enemy patrols. Our GM loves describing brutal battles and, as I understand it, one of Rune Quest's features is the fact that each hit strikes a particular body part.
Build-up
Anyway, there was a particular point at which the GM rolled a critical failure whilst attacking me. I had to roll to see what happened (i.e. how bad it was), but I rolled a critical failure too (100). He then rolled another critical failure! We're talking several realms of failure further than I've ever seen before. The GM's falling about laughing. Everyone in the room is laughing. I'm laughing. I had to roll again to see what effect this is going to have, but I roll 50 and the GM (still laughing) says "roll again, that's crap". So I roll again and roll 53 - again, he says "roll again, mate. That's crap - we want something good!". I roll again and get 57 (what's going on with my dice I have no idea), but I call out "naught one" (which would be a critical pass) and the game continues.
Question
The battle was particularly epic. In fact, we managed to fight off a stupid number of enemies and the last guy ran off scared. However, I feel dirty for lying about the dice roll. I'm sure the guys I play with don't really care (but I'm not sure any of them actually realise I lied...). Is there a particular dimension of hell reserved for me?
Are there any other major faux pas I should avoid?
