So that was my thinking - panache.
I like the idea of dual-wielding being the offensive versatility and "style" pick, where GWM becomes the offensive "power" pick. I thought about this while driving to work, as a way to expand the options for dual-wielding, and one-handed weapons in general. This goes along with changes/removal to CE/SS.
Off-hand Weapon Wielder
While wielding a one-handed weapon, or a versatile weapon with two-hands, you gain the following benefits:
You gain a +1 bonus to AC.
Attacks you make with a melee weapon you’re holding in your other hand, as part of two-weapon fighting, don’t use your bonus action. You can use two-weapon fighting even when the one handed melee weapons you are wielding aren’t light.
When you take any action other than Attack or Cast a Spell to cast a cantrip, you may make a single melee attack (or a weapon attack with a thrown weapon) as a bonus action.
You can draw or stow two one-handed weapons when you would normally be able to draw or stow only one.
This would go along with the following change to GWM:
On your turn, when you score a critical hit with a melee weapon or reduce a creature to 0 hit points with one, you can make one melee weapon attack as a bonus action.
Before you make a
n melee attack with a
two-handed heavy weapon
(or a versatile weapon wielded in two hands) that you are proficient with, you can choose to take a -5 penalty to the attack roll. If the attack hits, you add +10 to the attack’s damage.
My goals here are:
1) Classes with Extra Attack and limited spell use, and supplementary bonus actions, will favor GWM. This allows martial damage to keep pace with caster damage.
2) GWM being the only source of the -5/+10 mechanism slows degenerate builds like Hand Xbow with CE/SS.
3) Encourage versatile weapon use, by allowing the weapon to be useful for two different feats, which have some complementary features. The goal here would be to allow a fighter with both feats to take a turn like Attack with one-handed longsword, throw a dagger (using two-weapon fighting, so no BA required), then take the second attack using the longsword two-handed with -5/+10.
4) A weapon feat for primary casters like clerics and druids, allowing spell casting + a weapon attack. Possibly near the OP end for melee clerics with Divine Strike, but 8+ level clerics aren't usually using melee at all, and this doesn't synergize with cantrip use or
spiritual weapon. Still a concept I need to look for possible uses with.
5) Bonus action attack slightly devalues Rogue Cunning Action, but Rogues will still value a 2nd attack from two-weapon fighting or cantrip use from Arcane Trickster.
6) Allowing this feat with a shield might be too strong, with a Fighter/Paladin using Defensive Style could hit a 22 AC, Dodge, and still have one (fairly weak) attack. Debating whether to add (cannot be using a shield) to the requirements, or limiting the AC bonus to "wielding two one-handed weapons".