WEAPON PROFICIENCY, Baldur's Gate 2

Weapon Proficiency Baldur's Gate

On the Infinity Engine, weapon proficiencies most notably impact THAC0, damage and ApR in martial combat.

In Baldur's Gate 1, BioWare capped experience point progression before Fighters attained the ultimate in weapon proficiency, which is Grandmastery. 

Then, in Baldur's Gate 2, BioWare allowed players to reach GM but nerfed the proficiency table. 

That means, outside of certain mods that extend the XP cap in BG1 (such as DSotSC), or mods that un-nerf GM in BG2 (Baldurdash / teambg), we never got to experience True GM in the Bhaalspawn Saga. However, Icewind Dale 1 and Planescape: Torment both employ True Grandmastery.

Laughably, it is only BG2 that does not.

Weapon Proficiency Table Baldur's Gate

BG1, IWD1, PS:T

Weapon Proficiency	THAC0 Adjustment	Damage Adjustment	Attacks per Round (ApR)
Proficient	0	0	0
Specialization	+1	+2	+½
Mastery	+3	+3	+½
High Mastery	+3	+4	+½
Grandmastery	+3	+5	+1

Nerfed Grandmastery Baldur's Gate 2

BG2

Weapon Proficiency	THAC0 Adjustment	Damage Adjustment	Attacks per Round (ApR)
Proficient	0	0	0
Specialization	+1	+2	+½
Mastery	+2	+2	+½
High Mastery	+2	+3	+½
Grandmastery	+2	+4	+½

Thus, in BG2, all GM offers over Specialization is +1 to-hit and +2 dmg. And that costs us three proficiency points. For that price, we could get:

• Specialization in another weapon: to-hit +1, dmg +1 and ApR +½ and
• Proficiency in yet another weapon: no 4 point to-hit penalty

Why BioWare felt the need to modify TSR's AD&D 2nd Edition proficiency rules, I have no idea. I would trade BG2's ApR 10 nonsense for True GM and combat encounters rebalanced around ApR 5 max any day of the week. Not only is True GM by the rules, but the animations and sounds of the Infinity Engine were designed around ApR 5 max as well.

[1] Both IWD and PS:T are true to the proficiency rules except for the fact that, in IWD, Bows cannot be Grandmastered. And except for the fact that, in PS:T, Morte attains GM at 11th level (½ mil XP too early).

Weapon Proficiency Dual-wielding

When dual-wielding in BG2 (see dual-wield BG2), weapon proficiencies impact off-hand weapon to-hit, damage and speed factor, but not ApR.

Best Weapon Proficiency Baldur's Gate 1

In Baldur's Gate 1, the best weapon proficiency is Bow (for Composite Longbow), Small Sword (for Dagger of Venom) or Large Sword (for Drizzt Scimitar). Since we can only Specialize in Chargen, the best choices are Specialization in Bows and Specialization in a melee weapon grouping (**). If playing BG1 in the BG2 engine, we should choose Longbows and a melee weapon (Twinkle is a Scimitar, f.e.). If playing as a Mage, it's Missile Weapons for Darts all the way.

List of Weapon Proficiencies in Baldur's Gate 1

There are 8 weapon proficiences in Baldur's Gate 1 Original.

• Bow
• Spiked Weapons
• Small Sword
• Large Sword
• Axe
• Blunt Weapons
• Missile Weapons
• Spear

Best Weapon Proficiency Baldur's Gate 2

In Baldur's Gate 2, the best weapon proficiency is Flail because Flail of Ages BG2 is the best weapon by a long shot. Otherwise, Katana for Celestial Fury BG2. It is also best to get Specialization in Two Weapon Style for off-handing Belm BG2 or Crom Faeyr. In archery, Shortbow is a better proficiency than Longbow due to Tuigan BG2.

List of Weapon Proficiencies in Baldur's Gate 2

There are 15 weapon proficiences in Baldur's Gate 2.

• Bows
• Crossbows
• Missile Weapons
• Axes
• Clubs
• Daggers
• Flails
• Halberds
• Hammers
• Maces
• Spears
• Quarter Staves
• Great Swords
• Large Swords
• Small Swords

Weapon Style Proficiencies Baldur's Gate 2

In addition, there are four Weapon Style Proficiencies in BG2. The best weapon style is Two Weapon Style. The increased critical hit threat range of Two Handed Weapon Style is cool, but dual-wielding is almost always superior to two-handing (See ApR BG2).

• Two Handed Weapon Style: This weapon class allows the character to use a two handed weapon and receive special bonuses. If one slot is spent on this proficiency the wielder gets a +1 bonus to damage and a -2 bonus to speed when using a two handed weapon. A second slot spent on this proficiency gives a further -2 bonus to speed while wielding two handed weapons. The character will also score critical hits on a roll of 19 or 20 (instead of just 20).
• Sword & Shield Style: Anyone can pick up a shield and get its basic protection bonuses, but by spending slots on this proficiency an adventurer can maximize the benefits received. One slot spent gives a -2 bonus to AC against missile weapons. Another slot spent increases the bonus to a total of -4.
• Single Weapon Style: This weapon class is for characters who do not wish to use a shield but want some bonus when using a one handed weapon. With one slot spent on this proficiency, the wielder gets a -1 bonus to AC and inflicts critical damage on an attack roll of 19 or 20, if using a single weapon. A second slot increases the AC bonus to a total of -2.
• Two Weapon Style: (see: Dual-wield BG2) This weapon class allows the character to use two weapons at the same time with fewer penalties. A character wielding two weapons without a slot in this weapon class would suffer a -4 penalty with the main weapon and a -8 penalty with the off weapon. With one slot spent on this weapon class, the penalties are reduced to -2 and -6. A second slot gives the character no penalty with the main weapon and a -4 penalty with the second weapon. A third slot spent on the two weapon style reduces the penalty with the off weapon to only -2. Since we only receive one off-hand attack, Specialization (**) in TWS suffices.

Baldur's Gate 1	Baldur's Gate Races	Baldur's Gate Spellcasting
Best Classes Baldur's Gate	Baldur's Gate Items	Baldur's Gate Dual-classing
Best Spells Baldur's Gate	Baldur's Gate THAC0	Baldur's Gate Specialist Mages
Best Weapons Baldur's Gate	Baldur's Gate Armor Class	Baldur's Gate Proficiency
Best Companions Baldur's Gate	Baldur's Gate ApR	Baldur's Gate Thieving