Axe of Dwarvish Lords counts as a Sword of Sharpness, is it just ruled to be bludgeoning damage instead?  What happens on nat 20?  Same or different effect?

Axe of Dwarvish Lords is a battle axe and deals slashing damage. Why would it need to be ruled to be bludgeoning damage?

Apologies, I'm used to a hammer of Returning, and completely spaced that this weapon is an Axe, not hammer.  Thank you for catching my mistake.

So is a sword of sharpness able to hit creatures immune to slashing damage from non-magical weapons? It doesn't have a +1 but it's obviously magical...

Hugo, every magical weapon counts to go through immunity, you do not need a +1 for it.

Example: Moon-touched weapons count as magical for damage resistance too. 

How would this sword work with features that let you crit on rolls of 19 and 20? Would the 19 deal an extra 12 damage, and the 20 would deal 14 extra damage + the roll to remove a limb? 

The language is "roll a 20 on the d20" rather than "roll a critical hit", so I would say that's the rule as written. You could make an argument for your DM and discuss a compromise? Although if you crit on a 19, you're still doing maximum damage on double your normal weapon attack, so that might be reward enough. 

My question is what this line means:

When you attack an object with this magic sword and hit, maximize your weapon damage dice against the target.

 Is this just flavor text? Or does it mean something mechanically?

Quote from GracieIronic >>

My question is what this line means:

When you attack an object with this magic sword and hit, maximize your weapon damage dice against the target.

 Is this just flavor text? Or does it mean something mechanically?

Attacking an object f.e. Attacking a locked door or cutting chains. Kinda like they opened doors in SW: Phantom Menace with light-sabers.

New-ish player here... does  "roll a 20 on the attack roll" mean only a natural 20, or is that with any hit modifiers? Like if i have a hit mod of +2 and i roll a 18 does that count or no?

Yes it means only a natural 20.

Mechanically, instead of rolling for damage, use the higher number you could possibly roll.

A 1d8 will be a solid 8, a 1d12 is a solid 12, etc.

I feel like this has been nerfed way to much from previous editions. In 1e, all you had to do was roll an 18-20 to chop off a limb. Now you have to roll 2 nat 20s in a row.

So if you have a Sword of Sharpness and roll a natural 20 on the attack, does the damage dice get doubled, as well as adding 14 damage?  

Yes, the crit still functions as normal, but you also add 14 after calculating damage for the hit.

Ya, 1 in 400 chance to have the useful limb chop.  A 20 followed by a 20 is way nerfed

This being very rare seems so ridiculous to me. The 14 extra damage is nice when it happens but it only happens one time in 20 so you're talking about an average increase of .7 damage per attack. That's less than an uncommon +1 weapon would do. The lop off a limb is great, when it happens, but that's one attack in 400 so a handful of times per campaign and if you get it late in the campaign as this is a very rare item could be just once. Max damage to objects is fine but rarely going to be used. This seems uncommon to maybe a weak rare. 

Would a +2 sword of sharpness be overpowered for my level 10 Paladin?

They ruined this weapon, like many other areas of gameplay. Why can't Wizards hire talented people?

Quote from Nazianzus_Nazarius >>

They ruined this weapon, like many other areas of gameplay. Why can't Wizards hire talented people?

 you can just homebrew the rules in you own game man