| Stalker0 |
First of all, bravo on your attempts to clean up and standardize the various combat maneuvers. I like the basic mechanic of a CMB number very much. However, I feel that your current system has weakened the various maneuvers too harshly.
If we assume two fighters of equal strength and skill (equal CMB, we will say 10 each). In order for the first fighter to disarm the second (DC 25), he needs a 15+ on the die roll (30%). If we give him improved disarm, that's +2. He now needs a 13+ (40%). Even with training in the technique, he has a less than 50% chance of success. That's simply not fun for most players.
Let me suggest an alternative. First, we lower the opposed DC to 10 + CMB, granting a slight advantage to the attacker. In my opinion this is fine, considering that the attacker is effectively giving up his action to attempt an action that does not directly relate in the slaying of his enemy (ie doing damage).
Second, we incorporate your wonderful version of the grapple rules into the other combat manuevers.
For example, disarm:
Meet DC: You weaken your opponents grip on his weapon and pull him off balance. He suffers a -2 to attack rolls in his round.
DC +5: You disarm the weapon. It lands at the wielder's foot.
DC +10: You disarm the weapon, and can send it up to 10 feet from the wielder in any direction.
Trip:
Meet DC: The target is off balance for one round.
DC +5: The target is prone.
DC +10: The target falls prone and you can immediately follow up with an attack.
This provides granularity to the maneuvers, so they aren't as binary.