While I appreciate keeping some information like this away from players, as roguelike games tend to emphasize a learning curve. Information on this penalty and the dual wield would be nice to have to update the wiki at least for people that want to know.
It reduces your accuracy, quite minimal. (Unless you dual wield without dual wielding, then it cuts your physical damage in half)
Does the penalty show up in your stats? I dont notice the accuracy penalty in there when i pick a character who only has 1 weapon skill, and then stack dual weapons on him. I do notice that damage appears to be halved, ish, but its still usually more useful to dual wield for the item bonuses and elemental damages (as it should be.) Perhaps the accuracy penalty needs to be visible, and more pronounced, and a full list of the current debuffs caused by dual wielding should be in the debuff overlay. Maybe also calculated into the character panel so its not such a guessing game.
The penalty is that your melee power is not added to damage from that weapon. Thanks to Vehementi for running the calculations and figuring it out
Thanks! I tried to compare stats for two different weapons myself, but I didn't notice any difference.
@Patashu Ah, that makes sense. I never saw damage lower than the exact weapon stats when using an incorrect weapon, and now I know why .
I don't think it has anything to do with not adding melee power (as I am quite sure spells that boost Burliness/melee power do increase my melee damage), as if you look into the XML the "bad weapon" penalty is expressed as a percentage (something like 137%). The same goes for the "dual wield" penalty (which is something like 157%).