Does Beast-Friending a horse overrule the rider?

Question

A PC successfully casts Beast Friend on an NPC's horse while the NPC is riding on it (e.g. charging in battle). If the PC now suggests the horse to run away or lie down, does the horse simply do that, or does the NPC rider have a say in that?

The rules use both the terms "control" and "guide the actions". In the first case, I would see the rider having no more control over the horse, while in the latter I would believe the rider might counter with a ride check who has a better grip on the horse.

Answer 1

I do not believe this is explicitly covered in the RAW. The way I would handle it as GM would be to make it an opposed roll between the rider's Riding Skill if they tried to control the horse whilst the spell was in effect, and the caster's Arcane Skill roll when casting the spell.

Where it becomes tricky is whether or not to make the rider roll each round the spell is in effect, and you could argue for either approach depending on the feel you were aiming for with magic in your world.