Two Weapon Combat

Training in Two Weapon Combat (TWC or 2WC) allows a character to swing a weapon in their off-hand.

Ranks and Training Point Costs

Type	Square			Semi			Pure
Profession	Rogue	Warrior	Monk	Bard	Paladin	Ranger	Cleric	Empath	Savant	Sorcerer	Wizard
Max Ranks Per Level	2	2	2	2	2	2	1	1	-	1	1
Training Point Cost	2/2	2/2	2/2	3/2	3/3	3/2	9/9	12/12	-	12/12	12/12

Pros and Cons

The biggest benefit of two weapon combat is the extra swing that the character gets. There are a few things that are different when a weapon is swung in the off-hand, such as roundtime, attack strength (AS), and defensive strength (DS).

Roundtime

Roundtime is calculated based on the base roundtime of each weapon, the weight of the off-hand weapon, and the user's strength. Swinging two weapons at once is far faster than swinging each of the weapons individually, but only fast off-hand weapons add no penalty whatsoever to swing speed. For the lowest roundtime, the weapon in the off hand should be at least as fast as the weapon in the right hand and should not be very heavy. To use an off-hand weapon without penalty, you must have the following strength bonuses:

Off-hand Weight	Minimum Strength Bonus
3 pounds	+5
4 pounds	+20
5 pounds	+35

Two-Weapon Combat

A character trained in Two Weapon Combat has the ability to attack with a weapon in each hand. These attacks happen simultaneously, and far faster than it would take to swing each weapon individually. When calculating the roundtime to swing two weapons at once, it is best to think of them as combining to make a single custom weapon base with its own base RT.

Assuming the character's off-hand weapon is at least as fast and as light as their primary weapon:

TWCBaseSpeed = RightBaseSpeed + max(LeftBaseSpeed - 2, 0) + max(WeightPenalty, 0)

WeightPenalty = min(LeftWeight - 2 - STROffset, 3)

STROffset = trunc((STRBonus + 10)/15)

This means that most characters can use a 3-pound weapon with a base speed of 2 in their off hand as if it were not there. Characters with a 25 strength bonus can use a 4-pound weapon without penalty, and characters with significantly more strength can use further heavier weapons. Every additional second of base speed or pound of weight beyond that limit increases the base roundtime by 1 second.

This TWC base speed is used in all roundtime calculations, including the calculation of minimum weapon speed.

See the Melee Roundtime article for an in-depth discussion of the factors that go into the calculation.

Attack Strength

The AS of a swing takes into account the character's skill with the weapon itself, and their skill in TWC. 3/5ths of one's skill in the weapon type accounts for the character's AS, while 2/5ths are the character's training in TWC itself. Also, if a character's strength bonus is higher than the character's dexterity bonus, the off-hand attack will be limited by the character's dexterity. More often than not, this comes into play when a character uses the combat maneuver, Surge of Strength.

Additionally, a character that trains in TWC twice per level has no chance of "not finding an opening for the off-hand strike" when swinging at a target up to five levels higher than themselves. Less training reduces the chances of the off-hand strike from occurring. Training in TWC 1.5 times per level reduces the level of the guaranteed strike to like-level with the swinger, and training only once per level reduces the chances to 80% when swinging at a target that is the same level as the swinger.

Defensive Strength

TWC parry DS is the sum of the primary hand DS + Off-hand DS.

Primary Hand DS

Primary (right) hand parry DS uses the standard one-hand parry DS formula. One rank in the appropriate weapon skill is required to activate parry DS. This formula is also used for open-hand brawlers.

Primary hand DS = [(Weapon ranks + STR/4 + DEX/4 + enchant bonus/2) × stance modifier] + stance bonus

Stance	OFF	ADV	FOR	NEU	GUA	DEF
Modifier	0.20	0.30	0.40	0.50	0.60	0.70

Stance	OFF	ADV	FOR	NEU	GUA	DEF
Bonus	0	10	20	30	40	50

• The stance bonus is actually a part of the Evade formula but its inclusion with parry DS has been a long-standing practice.
• Truncate all values

Off-Hand DS (with weapon)

Training a minimum of one rank TWC is required to activate off-hand parry DS.

Off-hand DS = [(TWC ranks + STR/4 + DEX/4 + enchant bonus/2) × stance modifier] + (5 or 15 depending on weapon)

Stance	OFF	ADV	FOR	NEU	GUA	DEF
Modifier	0.10	0.15	0.20	0.25	0.30	0.35

• There is +15 bonus if the off-hand weapon is either a main gauche or sai. For all other weapons the bonus is +5.
• Truncate all values

Open Off-Hand DS

A character's DS with an open off-hand is calculated slightly differently than a weapon holder. Note that one rank in both brawling and TWC is required to activate open off-hand DS.

Open off-hand DS = [(TWC ranks + STR/4 + DEX/4 + enchant bonus/2) × stance modifier] + (5 or 15 depending on TWC training)

Stance	OFF	ADV	FOR	NEU	GUA	DEF
Modifier	0.10	0.15	0.20	0.25	0.30	0.35

• The +5 or +15 bonus at the end of the formula is determined by TWC training; a character with at least 0.5x TWC ranks per level receives the +15 bonus.
• Use the enchant bonus of UAC hand coverings when applicable.
• Truncate all values

Weapons and TWC

Weapons that require two hands to wield, such as the claidhmore and lance, generally cannot even be swung with a weapon in the off-hand, let alone used in two-weapon combat. Almost all one-handed weapons can be used in the off-hand, but there are a few notable exceptions. The so-called "bastard" weapons that can be wielded one- or two-handed via the GRIP have various limitations or outright restrictions in two weapon combat.

Weapon	Effect/Limitation
main gauche	Provides +10 DS when wielded in the off hand
sai	Provides +10 DS when wielded in the off hand
whip-blade	Cannot be used in TWC for lore reasons
pilum	Cannot be used in TWC
spear	Cannot be used in TWC, even when GRIPped one-handed.
bastard sword	Can be used only in the main hand, and only when GRIPped one-handed.
katana1	Can be used only in the main hand, and only when GRIPped one-handed.

¹A few katanas in the game were created before the actual katana weapon was coded. These "old-style" katanas were falchions (and possibly other weapon types) altered to be called a katana, and thus follow the rules of that weapon base

Resources

• http://www.play.net/gs4/info/skills.asp#twoweaponcombat
• http://www.play.net/gs4/info/combatguide.asp#factors
• Two Weapons Combat Officials folder
• Nilandia's guide on archive.org