How much gold would this weapon be worth?

Just got this sword from a Quest! Damn what luck!

I got it from my very first quest

how much money would the rapier cost?

does the damage also apply to dragonborn?

No, Dragonborns are Humanoid. But applies to Faerie Dragons, Dragon Turtles and Kobolds.

It varies immensely. Officially magic items only have a cost range, as buying them is in most setting a luxury at best, or just outright not an option. For a rare magic item like this the range is 501 Gp - 5000 Gp, so it just depends on who's trying to sell it, and how rare it is in the setting. If it's like the only one know to exist, probably closer to 5000, if there's dozens maybe it's on the lower end.

MSRB would be between 4000 GP and 39,999 GP since it is a rare item. So it depends on how vaulable the DM views it. That is even if your DM allows shops to sell magic items that are more rare then common quality. 

Would this do extra damage to Tiamat?

Technically no because she is considered a fiend, but I think most reasonable dm's would allow it

ya

Rare magic item cost in the DMG is 501 to 5000 gp

Quote from Samuel0702 >>

does the damage also apply to dragonborn?

 

 Yes, it does.  Dragonborn have the name dragon in it and are like little mini dragons.  Saying it doesn't apply to Dragonborn because their stat block says humanoid, means you have a rules lawyer that isn't looking at the overall picture or using common sense.

"For the purpose of this weapon, "dragon" refers to any creature with the dragon type"

Dragonborn may resemble dragons, but they are not actually related. at-least in the forgotten realms, Dragonborn were crated by IO, and aren't in any way related to dragons. just because they look similar does not in any way say they have the dragon TYPE

Quote from HarrisEyal >>

"For the purpose of this weapon, "dragon" refers to any creature with the dragon type"

Dragonborn may resemble dragons, but they are not actually related. at-least in the forgotten realms, Dragonborn were crated by IO, and aren't in any way related to dragons. just because they look similar does not in any way say they have the dragon TYPE

 

 

Beyond 20

 

 

 

 

 

 This is both RAW and RAI. Good show.

If you were to roll a nat 20 against a Dragon would the 3d6 extra damage be doubled as well?

Yes, a critical hit allows you to roll twice as many dice, no matter the source. A critical hit with a longsword would be 2d8+6d6+1+Str and a greatsword would be 4d6+6d6+1+Str. Bilbo the 5th-level rogue with 3d6 sneak attack and a rapier would do 2d8+6d6+6d6+1+Dex!

Does the damage apply to chimeras?

RAW no, as Chimera are monstrosities and not dragons.

Although you could decide that players could target the dragon head to deal extra damage (i would give them disadvantage to do so) or it could let the sword deal an extra d6 as the chimera 1/3 dragon lorewise.

Nice! Thanks