Infiniti2000 said:
Okay, so to leave the character tripped, (1) the ogre needs to hit, (2) the character needs to fail his reflex save, and (3) the ogre needs to successfully trip the character. Note that on #3, the character could possibly tear the weapon out of the ogre's hands. This is not as good as improved trip IMO, specifically because the attack occurs first.
Actually, it's at least as good as Improved Trip in most situations. The problem with Improved Trip is that it offers three opportunities to do no damage and consequently ends up seriously reducing a characters's damage output. The Ritiil does damage more reliably but trips less reliably. That's often a good trade since it removes a number of the calculations from using Imp Trip. (There's no need to say, "I may well put him down in one hit; there's no point in tripping him" for instance.) That is doubly true from the standpoint of an NPC who can pretty much be guaranteed not to face any of the "trying to trip this is a really really bad idea" situations that might make the Ritiil's inability to forgo the trip attempt a weakness. After all, most PCs aren't exceptionally strong large or huge quadrapeds.
Furthermore, the Ritiil is an option for anyone that has no prerequisites. Improved Trip is the second feat in a chain with an Int 13 prereq. (And it's kinda tough to come by a 13 Int if you're a monster like an orc or an ogre).
Math follows on the damage sacrifice of Improved Trip and the tripping sacrifice of the Ritiil
Improved Trip:
1. Touch Attack--relatively easy, but still at least a 5% chance of failure. If this fails, the attack deals no damage.
2. Trip check--in most cases, characters will be lucky to get a 75% chance of success on this (though ogres and other large creatures can get more of an advantage). If this fails, the attack deals no damage. (And you may be tripped in turn).
3. An ordinary attack roll against the opponent's prone AC. If this fails, obviously, the attack deals no damage.
If you have a 90% chance of success on the touch attack and a 50% chance of success on the normal attack, and a 75% chance of success on the trip, you end up with a 47% chance of dealing damage. While that seems pretty good, it represents about a seven point advantage in trip check scores--rather like a 22 strength character with Improved Trip trying to trip an ordinary 16 str character or an enlarged character with improved trip trying to trip your typical orc fighter.
Against more evenly matched foes--a fighter with Improved Trip against an equal strength fighter without it, for instance, the success on the trip is likely to vary between 50 and 66%. In a 66% trip success rate, with a 95% touch attack success, what would otherwise be a 75% chance of doing damage goes down to a 59.7% chance of doing damage.
Against a foe who is otherwise easy to hit--say a 95% touch attack chance and an ordinary 85% chance to hit--the odds of dealing damage stay at about 60% even though the chance of hitting on the normal attack went up to 85%.
And, against a foe with a good touch AC (let's say 85% chance to hit touch and a 65% chance to deal damage normally--a typical rogue, monk, or wizard with a +4 armor bonus), the 85% chance to hit, 66% chance to trip and 85% chance to hit on the follow-up add up to only a 61.4% chance to do damage.
By displacing the trip check to after the normal attack, the Ritiik enables characters to engage in the highly advantageous tripping game without much sacrifice of their damage dealing ability. (You end up with slightly less chance of tripping your foe but no reduction in the amount of damage you're likely to deal).
Running the math on the previous examples, the 90% touch AC/75% trip/50% normal AC situation resulted in a 67.5% chance of a successful trip with Improved Trip and a 47% chance of doing damage.
With the Ritiik, the character has a 50% chance of doing damage and, assuming a 20% success rate on the reflex save (reasonable since saves vs. damage dealt are pretty notoriously difficult to make) but only a 30% chance of tripping the enemy.
The second 75% chance to hit, 66% chance to trip, and 95% chance on the touch attack, the Ritill yields damage 75% of the time and a trip 39.6% of the time. (vs. a 62.7% chance of tripping with Imp Trip).
On the final example: 65% chance to hit, 66% chance to trip, and 85% touch attack, the Ritill yields damage 65% of the time, and a trip 34% of the time. (Vs. a 56% chance to trip with Imp Trip).
The ogres would only do that if they had combat reflexes. Instead, what would happen is that the characters would move in, provoke an AoO, get tripped, and then stand up. Unless the ogre had combat reflexes, he could not take the second AoO. Then, the next character would move in unmolested. I don't know if you've furthered modified the ogres, but ogres by default have a Dex of 8, making combat reflexes an extremely poor choice for a feat and worthless for this scenario.
