Forced Vertical Movement (Bull Rush / Hydraulic Push)

[Telmaski]

I've been playing with a guy who believe's that it's possible to use Bull Rush and Hydraulic Push to move people vertically, either launching them into the air or knocking them to the ground.

PRD said wrote:

Bull Rush Excerpt: A bull rush attempts to push an opponent straight back without doing any harm.

His argument is that up (or down) and away is still "straight back" by definition. Bull rush is pretty easy to argue that this interpretation is wrong, but Hydraulic push is the real aggressor as the effect can appear from any direction.

I know the rules are only assuming horizontal movement in this situations, but I'd like to back it up with text and I can't seem to find anything specifically saying that forced movement is relegated to the horizontal plane. I assume the only exception to this is when you are physically above/below your target, such in the case of flying or borrowing.

We're a pretty RAW heavy group, hence I'm looking for a very RAW focused answer.

Thanks in advanced.

[Silent Saturn]

In order to bull rush someone in any direction, you have to come at them from the opposite direction. Bull rushing him directly up would require you to position yourself directly beneath him, which means A) entering his square, and B) somehow getting between him and the ground he's standing on.

Since entering an opponent's square requires an Acrobatics check with a steep DC, ask him to find the rule for what kind of check he needs to make to wedge himself underneath an enemy's feet. He won't find it, therefore by RAW it can't be done.

As for Hydraulic Push, I seem to remember somewhere in the traps section there's a spring tile trap that does indeed bull rush its victim straight up. In this case, the other guy might actually be right-- he can't position himself for a bull rush, but a Hydraulic Push could, in theory, erupt from below.

[EvilMinion]

What about an earth elemental bull rushing from below? =)
Has a nice image to it, as the elemental bursts up through the ground and the guy goes flying!

Though theoreticaly, I suppose you'd want to come in on a slight angle, so he doesn't fall back down on your head.

Hmm... perhaps count the target as one size category larger (to account for having to push against gravity too), and resolve as normal from there?
Then apply falling rules from wherever they end up.

[BltzKrg242]

If you can get under a thing, sure you can bull rush up but you might find it hard to follow. So you push the guy up 5' then he lands on you.
now what?

[Sekret_One]

Now ... we ride!

[Kip TeaLeaf]

I, too, am wondering about hydraulic push, particularly its impact and water effect on feathered flyers.

Story: a medium harpy picked up my fellow Pathfinder, who was charmed to think the harpy was beautiful, and the harpy was about to carry him off. On my round, I wanted to use a downward vertical hydraulic push, or maybe angled downard and a backward into the harpy's face. My goal was to push the harpy back toward the rest of the party and toward the ground, to otherwise disrupt flying, and to soak the harpy with water in a further effort to disrupt flying. In short, I wanted to slow or ground the harpy, not simply damage it. I ended up not casting hydraulic push because I got charmed before I got my initiative, but... What would have been the result?

Dealing with flyers who fly away is a major pain unless you have a character with wizard/sorcerer spells like color spray... For a druid, a magus, and a bunch of fighter types, we didn't have anything except ranged weapons to hit a flyer flying away - unless hydraulic push would work the wonders I (the druid) would expect it to... I suppose I could get a roc animal companion and overpower myself, but I'm not a cheapass and like the roleplay/fun aspect of having my python. :)