Stormonu
NeoGrognard
On monsters, a lot of creatures that have the "claws" attack make one attack roll but the damage is combined into (usually) a single die. For example, a Lion does 1d6 (+3) with its single-rolled claws attack, representing two 1d3 individual claws rolled into one attack (if you roll a 1 for damage, only one of the claws is assumed to have connected). (Note: this first option can hurt Rogues quite a bit, and if used may be worth giving them Extra Attack at some point).
Weapon Combos:
1d3 main + 1d3 off-hand = 1d6 damage
1d4 main + 1d4 off-hand = 1d8 damage
1d6 main + 1d4 off-hand = 1d10 damage
1d6 main + 1d6 off-hand = 1d12 damage
1d8 main + 1d6 off-hand = 1d14? damage (there is a d14 die)
1d8 main + 1d8 off-hand = 1d16? damage (there is a d16 die)
OR, if you want a lower-powered version
Gain advantage on the attack (as if using the "Help Action" on yourself). Roll both damage dice, take the best result, but apply only one damage result.
Weapon Combos:
1d3 main + 1d3 off-hand = 1d6 damage
1d4 main + 1d4 off-hand = 1d8 damage
1d6 main + 1d4 off-hand = 1d10 damage
1d6 main + 1d6 off-hand = 1d12 damage
1d8 main + 1d6 off-hand = 1d14? damage (there is a d14 die)
1d8 main + 1d8 off-hand = 1d16? damage (there is a d16 die)
OR, if you want a lower-powered version
Gain advantage on the attack (as if using the "Help Action" on yourself). Roll both damage dice, take the best result, but apply only one damage result.