Sometimes when it comes down to fighting a rough opponent, it might be a better option to stop hacking at their massive HP pool and instead go for the part that really matters: their material goods!
In all seriousness, smashing a weapon is what your party might need to get the upper hand on an opponent.
However, anyone who has done any sort of armed martial arts will tell you it’s actually sort of difficult to really aim for an enemy’s weapon. Especially when they are very intent on hitting you in the face with it.
Pathfinder gives us rules for simulating this in a fight, though it can get pretty complicated.
Our job is to fight that complicated nature and break this down for you, our dear readers!
Sunder mechanics are phrased sort of weird in the SRD.
You can attempt to sunder an item held or worn by your opponent as part of an attack action in place of a melee attack. If you do not have the Improved Sunder feat, or a similar ability, attempting to sunder an item provokes an attack of opportunity from the target of your maneuver.
If your attack is successful, you deal damage to the item normally. Damage that exceeds the object’s Hardness is subtracted from its hit points. If an object has equal to or less than half its total hit points remaining, it gains the broken condition.
If the damage you deal would reduce the object to less than 0 hit points, you can choose to destroy it. If you do not choose to destroy it, the object is left with only 1 hit point and the broken condition.”
So as the demolition crew boss said to his workers, let’s break this down.
When you want to break someone’s weapon, you roll to attack it. This is a Combat Maneuver so rather than using your normal attack bonus vs your opponent’s AC. Rather you are going to roll your Combat Maneuver Bonus (CMB) vs your opponent’s Combat Maneuver Defense (CMD).
Your CMD is 10 + Base attack bonus + Strength modifier + Dexterity modifier + special size modifier + miscellaneous modifiers (Misc. modifiers are any circumstance bonuses to AC like deflection, dodge, insight, luck, etc.)
So you roll your CMB against their CMD. If you succeed, you manage to make contact directly with their weapon. This will provoke an Attack of Opportunity, so keep that in mind.
You then roll your damage like you are dealing damage normally. You then take a look at the item’s Hardness rating. Subtract that Hardness rating from the rolled damage. Any damage you rolled over that hardness rating does actual damage to the weapon/armor/item your opponent is wielding.
If the item takes over half its hit points in cumulative damage, it is considered Broken. If you manage to push it to 0 hit points, you can destroy it completely.
It should be noted that you can sunder multiple times in one full attack action. If you get multiple attacks per round, you can declare some of them sundering attacks against an opponent’s weapon, armor, or shield.
Let’s Look at an Example:
1) Aniuka sees an enemy halfling sighting down his crossbow to shoot her party member, Arisada, in the back while he is tangling with his own foes. Ani knows she can’t kill this halfling in one shot, but she may be able to break his crossbow so it can’t shoot this round. Ani moves into melee and uses a Sunder attempt.
She rolls her CMB and comes up with a 19. The Halfling’s CMD is only 17, so Ani makes contact. Ani brings her spear down to hit the crossbow. She rolls damage: 1d8+3, and she comes up with a total of 10 damage.
That is just enough to overcome the crossbow’s hardness and deal damage to the weapon. The Crossbow is at 0 hit points, and Ani decides to destroy it. Arisada is safe from getting a bolt in the back…for now.
Limitations to Sundering
There are a few limits to the Sunder Maneuver.
You cannot Sunder natural attacks or natural weapons. In essence, if you want to stop the monster from hitting you with its claws, then you are just attacking their limbs and therefore doing HP damage.
Magical Energy attacks (fire, frost, sonic, lightning, etc.) will do half damage to solid objects. You need to divide your damage by two, then apply the hardness.
The GM might overrule this if it’s a certain type of energy vs something that would counteract it. Example: Fire Damage against cloth or parchment, Sonic damage vs Crystalline objects.
Objects also take half damage from Ranged weapons, so attempting to break something with arrows or bolts is harder than smashing it in melee. Like with Energy, you divide your rolled damage by half and then compare that to the item’s hardness as normal.
Finally, Magical Weapons, Armor, and other gear gets a bonus against sunder attempts. For every +1 bonus a magical item has, it has 2 additional hardness. So a +3 Light Steel Shield would have 6 additional hardness for a total of 16.
When to Use Sunder
Some might wonder “why sunder when you can just kill” and I am here to tell you that Sundering will help you kill!
If your opponent has some really powerful or hard armor, you can make sunder attempts to crack it and make it less effective. Broken armor has its AC bonus haved, and its armor check penalty doubled.
This can also apply if your opponent has a powerful weapon. Disarm or Sundering can get that weapon in a state where they can’t bring it to bear against you.
Breaking it would be better than just a disarm, because it means even if they recover it, the item is unusable.
Sunder can also be very helpful if you DON’T want to kill your target. If you are wanting to bring your target in alive or wanting to stop a fight before it meets its grizzly end, breaking a weapon or someone’s armor can stop the fight in its tracks.
Improving Your Sunder
If you are wanting to get better at breaking things in the heat of combat there are really two options available: buffing your CMB or picking up Feats that will improve your Sundering directly.
Combat Maneuver Bonus is strictly the better option overall, and the first thing to look at. The best way to improve your CMB is to increase your Strength.
Your Base Attack Bonus is going to go up naturally as you level, and you probably won’t be able to increase your size bonus without some specialized magic. So Strength is something you should really focus on.
Sunder Feats are Combat Feats that will either improve your Sunder attacks, or add additional effects to them. Let’s take a look at a few here.
Improved Sunder: A must-have if you want to start getting your Sunder-on. Prevents AoPs when you attempt to sunder an item, gives you a bonus to sundering, and a bonus to defending against sunder attempts.
Greater Sunder: Improvement to Improved Sunder. Get additional bonuses when making a sunder attack, and any damage you do in excess transfers to the wielder.
Gate Breaker: Deal additional Strength Damage to anything you hit with a Sunder attempt.
Relic Breaker: Break something so hard the user catches fire.
Sabotaging Sunder: This is a weird feat, but basically rather than breaking something someone wears by smashing it, you can just render it inoperable. It has to be something they are wearing openly and not holding.
Shrapnel Strike: Smashing stuff so hard it causes AoE Damage.
Smashing Style: When using an Axe, a Hammer, or a Flail to sunder an opponent’s armor, you can get an attempt to bull rush or trip them at the same time.
Smashing Crush: When using Smashing Style, if you manage to damage the armor, reduce its hardness by 1.
Smashing Dent: Same as above, except you can also reduce its Armor bonus by 1 and increase its Armor Check Penalty by 1.Sundering Strike: When you get a critical hit, you also have a chance of sundering your opponent’s weapon!