[Caimbuel]

So I have some questions on Spellcasting and the Force used, and how the dice rolls add up.

Mainly for opposed rolls, Ive been reading the rules and I really dont understand how the opposed rolls work for resisting in this regard. From what I understand the number of hits for a Spellcasting + Magic test is limited by the force of the spell being cast, does this mean that for instance if I use a Force 7 spell and I roll 15 dice, and say I luck out and get 10 hits, does only 7 actually count? how does this factor for opposed rolls? Magic is really confusing me in this system.

[mtfeeney = Baron]

Correct.  If you get more than 7 hits on a force 7 spell, you don't benefit from the extra hits.  Those 7 hits will be the target for the opponent's roll, which is usually a Willpower or Body roll(plus counterspelling if they have it).

[Caimbuel]

Correct.  If you get more than 7 hits on a force 7 spell, you don't benefit from the extra hits.  Those 7 hits will be the target for the opponent's roll, which is usually a Willpower or Body roll(plus counterspelling if they have it).

So on a Force 7 spell all they can ever get is 7 hits, which is the target for resisting with BOD or WILL. Thats so much nicer from a GM perspective, I have one player who is rolling their spellcasting and getting like 10-12 hits, I know they arent using that high of Force. To know that the number of hits to resist is = to the Force of the spell makes my life so much easier. She was saying that the Monsters/NPCs have to make a BOD or WILL = to the total hits of her Spellcasting check. Which meant quite often that I couldnt save or stop her.

[mtfeeney = Baron]

The number of hits to resist is equal to or less than the Force of the spell.  If you cast a Force 12 spell and only get 3 hits, it's only 3 to resist it.

[Caimbuel]

The number of hits to resist is equal to or less than the Force of the spell.  If you cast a Force 12 spell and only get 3 hits, it's only 3 to resist it.

Wow, you made this a lot easier to use and understand. Thank you very much.

[Mason]

On another note, use of Edge on the casting roll bypasses that limit.

[mtfeeney = Baron]

On another note, use of Edge on the casting roll bypasses that limit.

You just blew my mind... 

[Mason]

On another note, use of Edge on the casting roll bypasses that limit.

You just blew my mind...

Yep. p. 182 SR4A, under "Force".

"A spell’s Force limits the number of hits (not net hits) that can be
achieved on the Spellcasting Test. So if you cast a Force 3 spell and get
5 hits, only 3 of those hits count. In other words, Force has a limiting
effect on spells—the more oomph you put into the spell, the better
you can succeed with it. This limitation does not apply to Edge dice
that are used to boost a spell."

Some argue that this means you need to roll Edge dice separately so that only the dice from Edge get this bonus, but most I have met just say the whole pool now passes the limit for simplicity.