Hi, I'm new here so I hope this is the right place for this question.  I was wondering when using your intelligence as attack and damage modifier through the arcane armor, with the bonus 1d6 attack with it, do you also apply the intelligence damage modifier to the bonus 1d6 damage?  As the rules state "When you attack with that weapon, you can add your Intelligence modifier, instead of Strength or Dexterity, to the attack and damage rolls"   that being said in the rules of the Lightning Launcher "Once on each of your turns when you hit a creature with it, you can deal an extra 1d6 lightning damage to that target". this extra 1d6 damage is from this weapon, so would the modifier be attached to it, or is it separate from the modifier, and it's own thing?

Thanks to those who took time to check this out, and especially to those who have ideas to share on this.

You wouldn't add your Intelligence modifier to the extra d6, no. The Strength or Dexterity modifier that the feature replaces with your Intelligence modifier only applies once per attack.

Thanks for the quick reply, and your thoughts!

Also, as a follow up question, does the extra 1d6 damage then count as a bonus attack? Or is it just tied to the initial attack?

It's just extra damage on the initial attack.

Nice!  Thanks again for your time and the help!  I was curious if it counted as such for the level 5 feature for an extra attack.  This helped me out on a few levels, so I appreciate it!

When a feature says "additional" or "extra" damage, that means it's being integrated into the initial triggering instance of damage; this means that if you roll a crit on that attack, you'd roll a total of 4d6 + INT mod.

Awesome! thank you too for weighing in, that's crazy about a critical!  Wow...  Makes me excited to think about that happening!

Also, remember that once you get extra attack at level 5, the extra d6 only applies once/turn when you hit ... so if both attacks hit then one would be 2d6+int and the other d6+int for damage.

When it says "add your . . . modifier . . . to the . . . damage roll", the damage roll is a game concept that can involve rolling multiple dice:

Damage Rolls

Each weapon, spell, and harmful monster ability specifies the damage it deals. You roll the damage die or dice, add any modifiers, and apply the damage to your target. Magic weapons, special abilities, and other factors can grant a bonus to damage.

. . .

When attacking with a weapon, you add your ability modifier--the same modifier used for the attack roll--to the damage.

Critical Hits

When you score a critical hit, you get to roll extra dice for the attack's damage against the target. Roll all of the attack's damage dice twice and add them together. Then add any relevant modifiers as normal.