QUOTE (itaipee @ Jul 26 2010, 11:50 AM)

well, the question is - if casting a spell in the second IP , also increase the drain by 1.
No.
QUOTE (itaipee @ Jul 26 2010, 11:50 AM)

If not - that mean I have quite good deal - for example having magic/force 3 , and casting 2 spells , then most of the chances that if I have 9 in the will+logic or will+charisma , then I will not suffer too much damage from these spells.
Magic/force 3? Magic 3 and Force 3 are not the same thing. Magic is your innate magical ability. It determines how much Force you can use. Force is the amount of power you put into a spell. It determines drain and also how many hits from the spellcasting roll you can use.
I'd go up to force 5, for general use. Force 3 spells are a bit weak.
There are ways to increase your drain resistance dice pool other than Willpower and your tradition's drain stat, such as fetishes (+2), focused concentration (+1 per level, max 2), focus will (+2), drain pact (+spirit's force).
QUOTE (itaipee @ Jul 26 2010, 11:50 AM)

to compare : magician that cast one spell with force 5 , then he likely to suffer from at-list 2 points of stun damage , not to mention if he want to kill himself by casting with force 10 ..
Drain is based on Force / 2, rounded down. Unless the magician is casting a spell with a -very- high drain code, and fails to get any hits on the drain test, they're not going to kill themselves by casting at force 10. Injure? Quite possibly. Kill? No.