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View Full Version : Pathfinder Combat Maneuvers - an analysis



Darkmatter
2009-09-24, 08:55 PM
I've seen a lot of discussion recently on the newly released Pathfinder ruleset (available as an SRD (http://paizo.com/pathfinderRPG/prd/index.html)). These rules are touted to help fix many of the problems with 3.5, notably the balance between the classes. In addition to changing the text of a number of spells to tone down the power of casters, the non-casters have been boosted, primarily though additional class features, improved feat chains, and changed mechanics. Whether or not this intent was brought about by the changes is, of course, a subject of contention. I figured I'd crunch some numbers on the new combat maneuver system and see how balanced it turns out to be.

I've spoilered most of the calculations here. They're a bit pedantic, so if you just want to skip to the conclusions you can ignore them - if you have issues with where I get my numbers, please read them.



How CMD and CMB are derived (spoilered for length):



Combat Maneuver Defense is calculated as (emphasis mine):


CMD = 10 + Base attack bonus + Strength modifier + Dexterity modifier + special size modifier

The special size modifier for a creature's Combat Maneuver Defense is as follows: Fine 8, Diminutive 4, Tiny 2, Small 1, Medium +0, Large +1, Huge +2, Gargantuan +4, Colossal +8. Some feats and abilities grant a bonus to your CMD when resisting specific maneuvers. A creature can also add any circumstance, deflection, dodge, insight, morale, profane, and sacred bonuses to AC to its CMD. Any penalties to a creature's AC also apply to its CMD. A flat-footed creature does not add its Dexterity bonus to its CMD.

This means that CMD is actually
10 + BAB + STR + DEX + size mod + circumstance, deflection, dodge, insight, morale, profane, and sacred AC bonus.

Combat Maneuver Bonus is calculated as (emphasis mine):


CMB = Base attack bonus + Strength modifier + special size modifier

Creatures that are size Tiny or smaller use their Dexterity modifier in place of their Strength modifier to determine their CMB. The special size modifier for a creature's Combat Maneuver Bonus is as follows: Fine 8, Diminutive 4, Tiny 2, Small 1, Medium +0, Large +1, Huge +2, Gargantuan +4, Colossal +8. Some feats and abilities grant a bonus to your CMB when performing specific maneuvers.

Performing a Combat Maneuver: When performing a combat maneuver, you must use an action appropriate to the maneuver you are attempting to perform. While many combat maneuvers can be performed as part of an attack action, full-attack action, or attack of opportunity (in place of a melee attack), others require a specific action. Unless otherwise noted, performing a combat maneuver provokes an attack of opportunity from the target of the maneuver. If you are hit by the target, you take the damage normally and apply that amount as a penalty to the attack roll to perform the maneuver. If your target is immobilized, unconscious, or otherwise incapacitated, your maneuver automatically succeeds (treat as if you rolled a natural 20 on the attack roll). If your target is stunned, you receive a +4 bonus on your attack roll to perform a combat maneuver against it.

When you attempt to perform a combat maneuver, make an attack roll and add your CMB in place of your normal attack bonus. Add any bonuses you currently have on attack rolls due to spells, feats, and other effects. These bonuses must be applicable to the weapon or attack used to perform the maneuver. The DC of this maneuver is your target's Combat Maneuver Defense. Combat maneuvers are attack rolls, so you must roll for concealment and take any other penalties that would normally apply to an attack roll.

This means that CMB is actually
BAB + STR + size mod + attack roll bonuses

Attack roll bonuses include, among other things, weapon focus, a fighter's weapon training class feature, and masterwork or enhancement attack bonuses on a weapon. This opens up a lot more avenues of optimization than just BAB + STR + size mod, as a not-too-close reading of the text would indicate.



I'll use a fighter here, since fighter and monk seem to be the classes intended to use maneuvers the most, and the fighter's more straightfoward. I'll look at tripping, grappling, and disarming, in my experience the three most commonly attempted maneuvers.

For each maneuver, a focused fighter will be getting: prereq (Combat Expertise for trip and disarm, Imp. Unarmed for grapple), Improved X, Greater X, both Weapon Focus feats, and Weapon Training in her chosen weapon. This gives us the following progression (6th level is put in there because that's when Greater X becomes available). STR is assumed to increase both from items and from leveling up, starting at 18, and ending at 30 (+5 level, +6 item, +1 tome or wish.) "Weapon" is the bonus to attacks from the weapon: MW at 5th, +2 at 10th, +3 at 15th, and +5 at 20th (seems reasonable to me). Tripping uses a tripping weapon and normal weapon bonuses. Grappling uses unarmed strikes, and no weapon bonuses - you could argue for enhanced gauntlets, which would make it the same as trip. Disarming uses a disarming weapon, which gives +2 to the attempt.

{table] Level | BAB | STR | Style Feats | Focus Feats | Training | Weapon | Tripping | Grappling | Disarming
1st | 1 | 4 | 2 | 1 | 0 | 0 | +8 | +8 | +10
5th | 5 | 4 | 2 | 1 | 1 | 1 | +14 | +13 | +16
6th | 6 | 4 | 4 | 1 | 1 | 1 | +17 | +16 | +19
10th | 10 | 6 | 4 | 2 | 2 | 2 | +26 | +24 | +28
15th | 15 | 8 | 4 | 2 | 3 | 3 | +35 | +32 | +37
20th | 20 | 10 | 4 | 2 | 4 | 5 | +45 | +40 | +47
[/table]

A non-focused Fighter will pick up a prereq and a style feat by 5th level and just use their normal weapon, taking close combat weapon training as their second style feat for tripping and grapple. Weapon focus feats won't be taken; for tripping, we'll assume a 5th level fighter springs for a 305gp masterwork spiked gauntlet to make attempts.

{table] Level | BAB | STR | Style Feats | Focus Feats | Training | Weapon | Tripping | Grappling | Disarming
1st | 1 | 4 | 0 | 0 | 0 | 0 | +5 | +5 | +5
5th | 5 | 4 | 2 | 0 | 0/0/1 | 1/0/1 | +12 | +11 | +12
6th | 6 | 4 | 2 | 0 | 0/0/1 | 1/0/1 | +13 | +12 | +13
10th | 10 | 6 | 2 | 0 | 1/1/2 | 1/0/2 | +20 | +19 | +22
15th | 15 | 8 | 2 | 0 | 2/2/3 | 1/0/3 | +28 | +27 | +31
20th | 20 | 10 | 2 | 0 | 3/3/4 | 1/0/5 | +36 | +35 | +41
[/table]

I'll compare these to the CMD's of a typical fighter, rogue, wizard, and dragon of the same level / CR. Misc. is odd AC bonuses - sort of arbitrary, and I'm generous with them (wizard gets a lot of these, for example). For feats, Fighter takes a style feat at 5 and Rogue and Wizard get Dodge at 5. Fighters get a bonus on disarm attempts from their weapon training.

Fighter:
{table] Level | BAB | STR | DEX | Feat | Misc | Total | vs. Disarm
1st | 1 | 4 | 2 | 0 | 0 | 17 | 17
5th | 5 | 4 | 2 | 2 | 0 | 23 | 24
6th | 6 | 4 | 2 | 2 | 0 | 24 | 25
10th | 10 | 6 | 3 | 2 | 0 | 31 | 33
15th | 15 | 8 | 3 | 2 | 2 | 40 | 43
20th | 20 | 10 | 4 | 2 | 5 | 51 | impossible
[/table]

Rogue:
{table] Level | BAB | STR | DEX | Feat | Misc | Total
1st | 0 | 2 | 4 | 0 | 0 | 16
5th | 3 | 2 | 4 | 1 | 0 | 20
6th | 4 | 2 | 4 | 1 | 0 | 21
10th | 7 | 3 | 6 | 1 | 2 | 29
15th | 11 | 3 | 8 | 1 | 5 | 38
20th | 15 | 4 | 10 | 1 | 7 | 47
[/table]

Wizard:
{table] Level | BAB | STR | DEX | Feat | Misc | Total
1st | 0 | -1 | 1 | 0 | 0 | 10
5th | 2 | -1 | 1 | 1 | 2 | 15
6th | 3 | -1 | 1 | 1 | 2 | 16
10th | 5 | -1 | 2 | 1 | 5 | 22
15th | 7 | -1 | 2 | 1 | 7 | 26
20th | 10 | -1 | 3 | 1 | 10 | 33
[/table]

Dragons are just appropriate CR dragons calculated from the (normal) SRD monster manual. They all have +4 vs. tripping due to 4 legs; large and larger have minor bonuses due to size. Note that the old red actually cannot be tripped unless the fighter enlarges due to size difference.

Dragon:
{table] CR | Type | CMB Total / vs. Tripping
1 | n/a | n/a
5 | Young Green | 24 / 28
6 | Juvenile White | 25 / 29
10 | Juvenile Red | 36 / 40
15 | Adult Red | 45 / 49
20 | Old Red | 54 / 58
[/table]



Let's look at the tripping, grappling, and disarming capabilities of a casual and a dedicated fighter build against appropriate opponents at various levels. The number in each column is the Combat Maneuver Defense for an average character, and the percentage is the chance our fighter has of pulling off the maneuver. Minimum chance is 5%, and maximum is 95% due to criticals.

Dedicated Tripper (invests 5 feats - combat expertise, 2x trip feats, 2x weapon focus. This is 1/4 of a fighter's feats.)
{table] Level | CMB | vs. Fighter | vs. Rogue | vs. Wizard | vs. Dragon
1st | +8 | vs. 17 (55%) | vs. 16 (60%) | vs. 10 (90%) | n/a
5th | +14 | vs. 23 (55%) | vs. 20 (70%) | vs. 15 (95%) | vs. 28 (30%)
6th | +17 | vs. 24 (65%) | vs. 21 (80%) | vs. 16 (95%) | vs. 29 (40%)
10th | +26 | vs. 31 (75%) | vs. 29 (85%) | vs. 22 (95%) | vs. 40 (30%)
15th | +35 | vs. 40 (75%) | vs. 38 (85%) | vs. 26 (95%) | vs. 49 (30%)
20th | +45 | vs. 51 (70%) | vs. 47 (90%) | vs. 33 (95%) | vs. 58 (35%)
[/table]

Casual Tripper (invests 2 feats - combat expertise and improved trip)
{table] Level | CMB | vs. Fighter | vs. Rogue | vs. Wizard | vs. Dragon
1st | +5 | vs. 17 (40%) | vs. 16 (45%) | vs. 10 (75%) | n/a
5th | +12 | vs. 23 (45%) | vs. 20 (60%) | vs. 15 (85%) | vs. 28 (20%)
6th | +13 | vs. 24 (45%) | vs. 21 (60%) | vs. 16 (85%) | vs. 29 (20%)
10th | +20 | vs. 31 (45%) | vs. 29 (55%) | vs. 22 (90%) | vs. 40 (5%)
15th | +28 | vs. 40 (40%) | vs. 38 (50%) | vs. 26 (95%) | vs. 49 (5%)
20th | +36 | vs. 51 (25%) | vs. 47 (45%) | vs. 33 (95%) | vs. 58 (5%)
[/table]

Tripping is great, just like in 3.5 - a dedicated tripper will spring for Greater Trip, which causes a tripped foe to provoke an AOO. You can use all of your iterative attacks to attempt a trip, with (as it seems to me) no penalty since your CMB is based on BAB. You get to follow up on a success with an opportunity attack from you and any allies who happen to be threatening. You can only be tripped back if you have below a 50% chance of tripping. The only caveat is that you cannot trip things more than one size category larger than you.

Grappling starts similar in difficulty and gets slightly harder at higher levels since you can't enhance your fists (enhancing gauntlets may be a way around this.) Disarming starts slightly easier thanks to disarming weapons, but gets harder towards the higher levels against other fighters due to their weapon training, becoming impossible at 20. Naturally, you can't disarm dragons.

It seems to me that the dedicated martial tripper/grappler/disarmer will be doing better using these mechanics than in core 3.5. The fact that attack increases add to the CMB check greatly outweighs the addition of DEX to the defense, especially since few things have both high STR and high DEX (some outsiders come to mind.)

Ultimately, and against my first impressions, I think this system is a vast improvement on that from 3.5e. It provides a unified mechanic, and what seems to me to be a success rate commensurate with the resources the character expends on the technique. I think it's a big step towards fixing the fighter (and, presumably, the monk) by both giving them interesting options in combat and a very reasonable chance of success. Maneuvers are more feat intensive, but everyone gets more feats. Tripping is mechanically about equal in power (the fact that you have to use up an AOO to attack is balanced, IMO, by the fact that everyone around the tripped party gets to make one too) but has become easier to pull off. Grappling likewise has similar effects, but is a bit easier to pull off without crazy size changes. Disarming has become much better since you can throw the weapon far enough away to be annoying, but still has limited usefulness.

Of course, I still see problems with the Pathfinder ruleset taken as a whole - you still can't trip a flying wizard, you still can't grapple a wizard with freedom of movement, and disarming a wizard still doesn't do much. The conclusion I've come to is that the combat maneuver system is hands down better than that in 3.5, it definitely is a power boost for the fighter (and, presumably, the monk), but in the end doesn't solve the fundamental power disparity between the martial and the casting classes.

Meek
2009-09-24, 09:03 PM
but in the end doesn't solve the fundamental power disparity between the martial and the casting classes.

In its defense, it probably wasn't trying to do that. I doubt any designer looks at trip, grapple and their ilk and thinks that it is in any way possible to have those tricks bridge the gap towards magic. It does make them more sensible to use in the situations where they are sensible to be used and easier though.