So there was this big debate some time ago...I can't find the thread but a discussion has come up in a game recently. In that discussion I had an idea that I wanted to run by people.
There is an argument that Athletics is the default defense for physical attacks - or Weapons/fists for melee attacks. That one doesn't have too much wiggle room to choose which skills to defend with.
Most people agree with this with standard physical weapons, but the debate is around spellcasting.
Where the caster gets to dictate the defense skill for the target. Like defending with Might to avoid a gravity spell, for example.
The rules are vague and some of the sample spells use other skills as defenses, so I thought it would be easiest to come up with an easy standard:
All physical attacks are defended with "default" skills as mentionned above: Athletics for ranged (assuming no stunts) and weapons, fists or athletics for Melee. Maybe a bit of wiggle room depending on the situation but, as I said, it's the default. This counts for evocations because they are, by their nature, physical. (mind magic aside)
If you could somehow set up a maneuver or declaration which you could invoke, the target could be compelled to use another skill. So you "blind side" someone forcing them to take the hit in the body instead of dodging or parrying your weapon. That would compel them to use Endurance to defend.
A spell wouldn't exactly need any declarations because it's pretty much built into the spell. So the wizard still gets to make custom spells, but they don't always work that way all the time (the compel gets turned down).
On one hand, it seems like the game is already built to work that way. On the other hand, it makes wizards spells compel machines and might be abused to get enemies to burn their FP's.