So by that, humor the new guy.
Ball Lightning, combat, indirect, physical, Area
Declare spell, declare target, declare force. Say it's 6.
Roll spellcasting. Count the hits. (say I get 4 hits). Keep all the hits, because it's lower than the Limit of the spell's Force.
Check for scatter (more than 3 hits, no scatter)
Check for hit. No dodge, but presumably "Run for your life" or similar interrupts that apply to grenades can give you a chance to reduce damage.
If you haven't reduced it, or gotten out of the AE some way, take the hit. Base DV is 6P v-6 or 6S v-6 (Damage depends on 'source or target'?) Combat spell, I'm assuming you're blowing stuff up, so base DV is 6P v-6.
If they didn't RFYL, 4 net hits, so damage is 10P v-6 to everyone hit.
You resist 5 drain. Stun if your magic is 4 or higher (your hits).
They resist 10P damage, using body+armor+nonconductivity. with -6 (to armor only, not body or nonconductivity parts of the pool).
Correct?
Stun if your magic is 6 or higher the force of the spell selected.
Otherwise yes and if they take damage they suffer electrical special effect see page 170 of the core.
As to ShadoccatX's point I think damage is 7, to me it's slightly unclear, the wording it is as follows
"Unlike grenades, you get to add your net hits on
this test to the Damage Value of the spell, but only if you
beat the threshold; otherwise the spell still detonates, but
the hits are used to reduce scatter by one meter per hit"
Page 283 of the core.
Net hits an awkward phrasing on simple check. But I think that what is intended.