The description says, "It deals lethal damage, even to creatures with armor bonuses." I assume this means on an attack, not on a combat maneuver. However, the flavor text says "This whip has a series of razorsharp blades and fangs inset along its tip." This implies that it will damage anyone being hit by it.
Interestingly it was the GM who thought it might cause damage, because I was using it to trip an ally (long story); I argued that it doesn't, because that would be overpowered. But I figured I should check.
I would say that the answer to the question is, "no damage on the trip." I only say this because the Snag Net weapon actually has the following text in its weapon description:
Snag Net: This short, wide net is covered in barbed loops and slipknots. It works like a typical net exotic weapon, except it has the trip weapon special feature. If you entangle an opponent and hold the trailing rope, on your turn in place of a melee attack you may make a trip combat maneuver check against that opponent; if you succeed, you may trip the opponent or deal 1 point of piercing damage to the opponent. The concentration DC to cast while entangled in a snag net is 17 + the spell's level. The Escape Artist DC to escape a snag net is 22.
However, your GM is free to make a houserule that the whip still does damage, maybe without strength or however he wishes to work it.
Ah! A good argument. Thank you.
And longswords are sharpened pieces of metal, but they don't do their damage on a trip with them either.
All weapons do damage of some kind (that's the point of being a weapon) and many of them can be used to perform a Trip maneuver. None of them do damage and Trip at the same time.
I guess I shouldn't say "none" because I haven't read every weapon in every supplement, maybe there is one that somewhere does, but I will say that if there is, then that weapon has specific wording to allow it to do damage while tripping.
Otherwise, you pick one - use the weapon to hurt your enemy (roll hit and damage) or use the weapon to trip your enemy (roll CMB).
As for the specific Scorpion Whip, the text you quoted is to override the normal whip that deals only non-lethal damage to armored targets - the quoted text makes it clear that the scorpion whip works differently than other whips, not that it works differently than other trip-capable weapons.
All weapons do damage of some kind (that's the point of being a weapon) and many of them can be used to perform a Trip maneuver. None of them do damage and Trip at the same time.
I guess I shouldn't say "none" because I haven't read every weapon in every supplement, maybe there is one that somewhere does, but I will say that if there is, then that weapon has specific wording to allow it to do damage while tripping.
Otherwise, you pick one - use the weapon to hurt your enemy (roll hit and damage) or use the weapon to trip your enemy (roll CMB).
As for the specific Scorpion Whip, the text you quoted is to override the normal whip that deals only non-lethal damage to armored targets - the quoted text makes it clear that the scorpion whip works differently than other whips, not that it works differently than other trip-capable weapons.
That was my argument at the time.