I totally disagree with the claim that the RAW is clear on this issue.
I also disagree with the claim that the mount is not a combatant. Of course it is. It isn't a Mini Cooper. It's a creature, with stats, attack rolls, damage rolls, etc.
Do some of the posters' assertions rely on the assumption that the character was riding a warhorse? Well, he wasn't...he was riding a tiger (trained for war by House Vadalis in the Eberron setting). But that shouldn't matter...for a discussion on the RAW, it is a war-trained mount.
Anyway, the RAW does say that the mount acts on the rider's initiative count and moves as directed by the rider. But the unspoken assumption there is that the mount is capable of performing actions at the moment it is given direction. If it is paralyzed, stunned, dazed, etc., its actions are limited. Thus, my earlier post stating that "a mount acts on the rider's turn" does not mean "if the rider can act then the mount can act" but rather "if the mount can act then it acts on the rider's turn."
The RAW says that a creature can be surprised. The RAW does not say that the creature's ability to be surprised disappears because he has a rider on its back. Am I wrong here? If so, point out the RAW that says so.
I think that ruling that the mount doesn't need to make a surprise-related role is a valid ruling because it can make combat simpler. But I assert that it isn't RAW. I also think my ruling isn't RAW simply because I don't think the RAW addresses this issue directly. But I do think it fits in closer to what is (and what is not) written in RAW than does the "no mount surprise" ruling.
And please, no "not another RAW fanatic" talk. I just said my own ruling isn't RAW.
Bottom line, the issue is debatable, and what works best differs from campaign to campaign. But if you assert that I made a bad ruling that outright contradicts the RAW...then prove it.
Thanks,
Atavar