@DrZaiusAs per Street Magic, Background Count does two things:
- It reduces Magic attributes by the absolute value of the rating
- It adds +1 to the Force of spells per point of absolute value of rating for Drain calculation
It also reduces sustained spells, wards, foci, etc... by a value of the BG's absolute value. Since that spell Stephen casted earlier was at F:3, as is his sustaining, they didn't collapse so they are still active.
So Stephen's Magic goes down temporarily -2, and the Force of spells for Drain calculation goes up +2
So with an effective Magic rating of 3 (5-2) you can't even cast a spell at Force 7, since that is now beyond twice your Magic rating. Might have to drop it down a bit. And insofar as your Magic rating does increase, there
IS effective a pool penalty, since the attribute has decreased. Though to be nice, I'll say since that previous roll isn't even possible, you can reroll, modify the Force of the spell, and hope for better results.

Don't forget that if you cast at Force 6 it does count as overcasting and it is Physical Drain instead of Stun.
@MartinAlso, I didn't realize that shorting the machete down to half a meter would make it ineligible for Reach purposes. I really just didn't want to give him some giant sword when he really just wanted to hack a bitch up. I supposed it's a bit late to go back now, but we will use the Cougar Fineblade stats that Combat Mage posted above and go with those. Next time I throw out a machete it'll be longer.

And Martin, give me a melee defense roll.
@LamhsleaA flash-bang won't do what you're trying to do to that sniper. A flash-pak however, will. If a flash-pak it what you meant to purchase in chargen I'll let you switch one out retroactively so you can use it on the sniper down the alley. It'll blind him temporarily while you make your getaway. A flashbang would just more than likely go off and Stun both you and El Mono. You can read about the two on page 324 of SR4A.