Magic Conflicts

["Michael Kilgore" <khaakon@lycosmail.com>]

There are some cases where two spell are cast and they do different things.
Granted these situations don't happen very often (I can think of only one
case), this subject may be something worth discussing as this information is
not in the book.

The one case I seen was where someone cast a spell to open a door (a
supposed experimental rank 2 or 3 A'tena spell) that had seal cast on it.
The GM ruled that the two spells were opposing each other and had the player
roll a number of dice equal to the power of the spell and he roll a number
of dice equal to the seal spell's power.  Needless to say, the mighty seal
won the battle.

How about Clarity (Isis) versus Pith (Mind Twisters)?
Soul Hold (necromancy) versus Deliver (Anubis)?
Air Temperature (air) versus Change Temperature (Common)?
Quicken (Movement) versus Slow (Movement)?
Wax (Earth) versus Wane (Earth)?
Adamant (Earth) versus Sunder (Common)?

I imagine there are many more examples.  So, what is the standard way of
handling these conflicts?

Thanks,
Mike