Anyone got any clues on where to look how to do this?

Wanting to do an effect where everything within X area of a spell is knocked down.

I tried using Push Force in scripting, but it only causes the single actor who was hit by the spell to be knocked down instead of applying the push-force script to all NPC's hit in the area. As far as I am aware, this is the only way to get NPC's to knock down, so it would rather svck to have it so AoE casts cannot apply any script effects to anyone except for the single target hit by the cast.

I use that affect myself, and yes, it only applies to one NPC. That's what I needed, so I didn't have to go any further. You might want to take a look at the Explosion http://www.creationkit.com/Magic_Effect. I haven't used it though.

There doesn't appear to be an explosion magic effect. However you can set an explosion visual effect.

It must be possible, because Unrelenting Force does just this. However the script it uses is very basic, and implies that it only affects one person (and I've copied it exactly), so I feel like I'm missing something and/or Unrelenting Force is a hardcoded effect.

the AoE needs to be something like a cloak spell (fire and forget, self)

once the AoE is cast on yourself (or whatever target), everything in proximity as determined by area/magnitude of the spell will cast an additional magic effect on the actors affected by the cloak.

this contact magic effect is where you would make a script archetype effect using pushactoraway