slide casting, and attacks of opportunity

[prileska]

Impassable Wall Stance
Prerequisites Attack of Opportunity
[...] when you critically hit with an Attack of Opportunity triggered by a move action, you disrupt that move action.

Attack of Opportunity
[...] the trigger was a manipulate action, you disrupt that action.

Would that then disrupt slide casting? Since it's a manipulate action, and a move action?

"After you use Striking Spell and start Casting a Spell that takes 1 action or more to cast, you can Stride or Step as part of that Cast a Spell activity."

[Lightning Raven]

Yes. Absolutely. You can choose to Step, but you're still using that Manipulate action, so you better hope that the attack isn't a critical hit.

But I don't think it would disrupt if the Magus was using the spell outside of a creature's reach and then getting in... At least I hope it doesn't. Otherwise, yet one more issue to be tossed in "Problems with Hold The ChargeStriking Spell" pile.

[prileska]

you'd still trigger with the movement though; so it probably would.

[biphenyl]

The movement component, whether stride, step, or teleport, would follow the rules for subordinate actions in the sidebar on page 462 of the core rulebook. So a slide Stride would only trigger reactions when a Stride normally would, it doesn't gain additional traits etc. even though it was triggered by the Cast a Spell activity.

Likewise if you cast out of something's reach and then slide Stride through a threatened space, only the subordinate Stride action risks being disrupted by Stand Still/Impassable Wall Stance/etc.