Normally, BTB, ANYONE may attempt to perform a combat parry by giving up ONE of his attacks (if he has multiple, whether via high level, or having two weapons). So a monster or PC who has 2 attacks a round (or more), could do ONE normal attack, and shift his 2nd attack into a Combat parry. It matters not whether that 2nd attack a round is cause you have two weapons, or are high enough to get 2 proper attacks. BUT doing this costs one of those attacks. You can also gain a “Free” combat parry, via certain weapon fighting style specialties.
Two weapon fighting specialty, gives a free parry Every 2nd round. The same happens for someone with Two handed weapon fighting specialty. Weapon and shield fighting specialty though gives one free parry every round, WITH the shield only.
To start with, the attacker rolls his normal to-hit. Take his thac0 and minus the defender’s AC. What ever the resultant number, over what was needed to hit, sets his “To beat what is needed” roll for the defender’s parry.
THEN the defender, has to roll his own to hit roll, and if using a shield has to “beat” the number that the attacker set. However if using a shield, they only have to equal it.
Doing so with a shield, if one does NOT have the ‘weapon and shield fighting style specialty, doing this, gives up the AC bonus of the shield for the REST of the round. Additionally, when parrying with a Shield, any AC Bonus the shield has, from magic, does NOT apply normally, to the parry. Though there are certain magic shields, that DO give that bonus to the parry rolls!Example: Bombast the Human fighter, has an AC of 3. An Ogre trying to hit him with his club, which has a thac0 of 15. will hit on a 12 or better. So if he rolled a 17, he would set the “TBWIN” number as a 5. IF Bombast tries to parry with his shield, he only needs to ‘hit’ the ogre, by 5, to successfully parry the club strike. BUT if he uses his sword, he’d need to ‘hit’ the ogre by 6 or more.
REGARDLESS Of scores, if an opponent hits with a natural 20 on you, YOU MUST ALSO get a natural 20 to parry the blow!!! Additionally, if trying to parry a blow, from a monster that normally would need magic to strike, one still must have magic, to parry the blow. So if using a shield, they must have a magical shield. If not, they cannot parry. This only applies if the monster, is using Natural weaponry, vice a melee/missile weapon.
This then, gets modified by the size difference in weapons though!!!
For each size difference UP OR DOWN of the weapon (or size of the monster using natural weaponry), there is a +2/-2 penalty. So If say a half-elf wielding a SHORT SWORD (Size S weapon) tries to parry a blow from a Long sword (Size M weapon), his attempt to parry has a -2 penalty applied to HIS ROLL. Where as if the one wielding the long sword, tries to parry the short sword, he gains a +2 to his roll to succeed at it! Additionally a WEAPON can only parry another weapon's blow up to 2 sizes UP (OR DOWN). So a Size S dagger, can parry a halberd (Size L), but cannot parry a Giant's blow. Neither can that giant club parry the dagger!
Buckler and Small shields (human size that is) are considered size S, medium shields are size M, while large or body shields are size L.
Parrying blows from foes with high strength, can ruin your shield or weapon used. IF YOU Shield BLOCK an attack from a foe that has a 16, 17, or 18 (no %) Strength, at the END of that combat Round, the player with the shield must make an Item save vs Normal blow, or see his shield shatter. However, if the foe has 18% or greater strength, the item save is versus Crushing blow instead. So a standard wooden shield would need an item save of 7, where as a metal shield would need a 4 or better. If, however you use a weapon to parry, the save is always vs crushing blow, if the opponent has a 18 or greater strength, its only normal blow for 16 or 17 strength!
Bombast as mentioned above, is a 5th level fighter, with a 18/56 Strength (+2 to hit, +3 to damage), 15 Dexterity (-1 AC), wears +2 hide armor, carries a medium shield, and uses a +1 broad sword that he is specialized in. He does not have any style specialties or shield proficiencies. He has a 3/2 attack rate with his sword, going 1/1 in every odd round, 2/1 in every even round.
He is leading a group of seven total characters (him, 5 other players and one henchman), when they encounter an armed group of a dozen Hobgoblins. The leader of which, is a 4th level fighter, with a 17 strength, is specialized in the Long sword (which is +1, but grants a prayer effect on the wielder, once every day for 6 rounds), and wears Splint mail, with a large shield. Likewise, he has no style specialties or shield proficiencies. Likewise, he has a 3/2 attack rate.
The Hobgoblin leader issues a challenge to the party, and if one wins, they will leave the rest be. Bombast, being the party’s leader, accepts.
Both are Armor class 3, so The Hobgoblin will hit bombast on a 10 or higher, while Bombast hits the Hobgoblin leader on a 9 or higher.
Round one, Bombast goes full defensive, doing a full on parry, adding 3 to his Armor class (level / 2 +1), so is now only hit on a 13 or higher. This will allow him to gauge his opponent and hopefully not take damage. Luck shines on him, as the Hobgoblin leader rolls a 11, which barely misses, thanks to the full parry.
In round two, both Bombast and the Hob leader, are on their 2/1 attack round. Bombast elects to use his 2nd attack, as a parry, while the Hob leader is attacking twice. Bombast loses initiative, and the Hob hits, on a 12 die roll for his first attack. Bombast can now try to parry, or wait till the 2nd attack to choose to parry or not. He elects to parry the blow now, and will also need to roll a 12 or higher (1 over the needed hit by the hobgoblin). He rolls a 14, and succeeds.
Then Bombast makes his to hit roll, and misses.
Then the Hobgoblin makes his 2nd attack, and misses. Bombast then rolls an item save vs normal blow for his sword, and makes it (rolls a 12 on the die).
In the 3rd round, Bombast goes first, and scores a nasty hit on the hob leader, with a 16 on the die. If the hob wishes to parry it, he will need to roll a 18 to succeed at it. He elects NOT to, and takes damage. Then he realizes, “HEY I have a prayer power in my sword, and kicks it in, gaining a further +1 to hit and damage)”. So that’s his action for the round. His thac0 is now the same as Bombast’s is.
In the 4th round, Bombast wins initiative, and like before, is opting for one hit, and one parry. The Hob leader, likewise goes for one blow and one parry. Bombast rolls first, but rolls only a 7, so misses. The Hob leader then gets his first strike, rolling a 14. So the Hob leader hits by 5 over what was needed. This means Bombast now needs to roll a 16 to parry, but fails, taking some damage.
In the fifth round, bombast wins initiative again, and gets a natural 20 to hit. This means the Hob leader, will also need a natural 20 to parry the blow. He takes a nasty wound. Another hit like that, and he may have to yield the battle.
In the sixth and final round, both again opt to parry each others blow. The Hob leader goes first, and rolls a miss (3 on the die). Bombast gets his first blow, and rolls a hit with a 17 on the die.. The Hob leader will need to roll a 18 or higher, to parry, elects to do so, but misses (he got only a 14). The damage he takes, is a bad blow, and so he yields..
Several months later, Bombast has enough XP to train to 6th level. With the weapon slot he opened up, he takes specialty in the Weapon and shield fighting style, thus gaining him a free parry to use. His Thac0 drops to 11, and he has a thac0 for his shield of 13. His party is now up to 10 strong, 1 more priest pc, and 2 more henchmen.
A week after training up, Bombast and crew, journey to an area they heard a rumor of an abandoned church. As Bombast closes in, he spots a barred door (from the outside), which seems strange. After unbarring it, he them kicks it in, and stands in the door, while an ally holds a lantern up, and is almost surprised by the onrush of a humanoid beast wearing rags (a monster known as a Z-throk, a relative of the Ghoul and Ghast family of undead). This is his first encounter with them, so he doesn’t know of their need for magic to strike. The Z-throk has a 13 thac0, and an AC of 2. Bombast thus hits IT on a 9 or better with his sword. The Z-throk hits him on a 10.
The first round, the beast wins initiative, (he must still be startled), and manages to roll a 7 for his first claw, a 12 for the second claw and a 16 for the bite. So the first claw misses, the 2nd claw hits by 2, and the bite hits by 6. Bombast, not realizing what the monster is, thinking it is just a ghoul, decides to shield parry the bite with his free parry. This means he will need to roll a 15 or better to parry the bite. He rolls a 18, and yells in happiness “He parried the blow. YAY!”. Then his player screeches in horror, after the dm says “So your shield arm swings in front of the monster’s bite, but seems to do nothing to affect it. The beast bites THROGH the shield, tearing a chunk off your arm, while the claw hits on your left side.”
Starting into round 2, Bombast, screams “I think we have undead here”, and one of his Priest companions, succeeds in a turn roll, but NOT before the beast can strike him again. The other priest, is too far back to attempt so spends the round moving. Bombast thinks “I couldn’t parry with my shield, maybe my sword will work”, so elects to give his 2nd attack up, to parry just the bite (as it was the nastier hit). The beast rolls a 8, 8 and a 17, hitting with the bite again. Bombast needs to equal that 17, to parry. He rolls a 18, and succeeds in parrying with his broad sword.. Since the beast has no rated strength, the DM declines to make him make an item save for the sword…
In round three, his 2nd cleric ally is in range to try a turn now, and succeeds. They hold the beast back, while they rummage in the church, finding a dead body with a magical wooden shield in (medium size). Bombast asks if anyone in the party will object to him claiming it, and he does so, gaining a +1 medium shield out of it!.. YAY.. This now drops his AC to a 2.
Two days later, the party encounters a pair of Ettins. Both size G foes wielding size L weapons. They are AC 1, and thus Bombast will hit on a 10 with his sword, or 12 with his shield. The Ettin however, has a 10 thac0, so hits Bombast with a 12 or better!
The first one, gets in Bombast’s face, while the other gets with the other 2 fighters in the party. Bombast easily wins initiative on the first round, and so declares he will shield parry one of the monster’s clubs. His broad sword takes a chunk out of the Ettin’s hide. Then the Ettin counters. His left hand club, strikes with a 15 on the die (3 over what was needed to hit), while the right club, barely misses with a 10 on the die. Bombast decides again to shield parry, so he will need to roll a 15 to do so, and lucks out with a 18 on the die, parrying the Ettin’s mighty blow.
However, he rolls VERY poorly for his newly acquired magical wooden shield, and watches as it Shatters under the Ettin’s mighty blow!. Now without a shield, his AC goes up to a 4.. EEK.
In the 2nd round, he ops to give up one of his two attacks to parry. The Ettin again loses initiative, and Bombast’s first blow strikes again. The Ettin being dumb, doesn’t parry. Takes the hit, grunts, then counters. His left hand blow misses badly, rolling a 3. BUT the right hand club scores a Mighty natural 20!. Bombast’s player realizes he will Also need to roll a 20 to parry it.. BUT comes no where close.. The blow being doubled, greatly wounds Bombast. EEK!