This may fall under GM call (YMMV) and the "unusual solutions" clause of the Guide, but I wanted to ask this here just in case other GMs have other ways to figure this out.

Say one of your players comes up with a unique solution to dealing damage, such as "we drop the piano out the window on top of the guys trying to beat down the door" or "I just rolled a natural 20 on a strength check - I'd like to pick up the blacksmith's anvil and throw it at them" or "I have an anchor/ship feather token I'd like to throw at them."

In non-combat situations, GM-call is GM-call, but during combat, where things have specific hp and weapons do XdY+Z damage...how would you handle something unusual like that?

Well, throwing the anvil is clearly an improvised weapon. As for dropping pianos and anchors and boats, aren't there rules somewhere for damage from falling objects? Or am I imagining things?

Come up with something on the fly that both rewards the player for creative thinking and doesn't completely negate the threat/encounter. The reason for the latter is to prevent the game devolving and so the spotlight doesn't shine too brightly on that player vs the rest of the table.

Well, throwing the anvil is clearly an improvised weapon. As for dropping pianos and anchors and boats, aren't there rules somewhere for damage from falling objects? Or am I imagining things?

Yes, falling object damage is covered in the Core Rulebook. This just came up yesterday in a PFS scenario I ran, because the scenario actually had a large creature throwing things at the party, and the adventure specifically says to use the falling object rules for damage when this happens. It even references a page number, which I'd give you if I had the scenario in front of me. I think it was 2d6 damage to get hit by a falling medium sized item.

Falling rules cover falling items as well.

Throwing an object would use the improvised weapon rules, and I think within those rules there might be a modifier for an object that is not aerodynamic.

I don't believe you could activate a feather token after you've thrown it. So you'd have to be able to throw the anchor yourself.

So the OP was asking this for me and a character I'm working on and we decided that as per the rules of improvised weapons, if my character wanted to throw a 10 lb anvil, it would do the equivalent damage of a 10 lb Heavy Flail (1d10) and if he wanted to throw a 14 lb anvil it would do the equivalent damage of a 14 lb Earthbreaker (2d6).

So the real question is: what if my character wants to throw a 50 lb anvil? Or a 100 lb anvil (assuming he is strong enough to do so)? There are no weapons to compare this to as per the improvised weapon rules and we couldn't decide on what to do.

So the OP was asking this for me and a character I'm working on and we decided that as per the rules of improvised weapons, if my character wanted to throw a 10 lb anvil, it would do the equivalent damage of a 10 lb Heavy Flail (1d10) and if he wanted to throw a 14 lb anvil it would do the equivalent damage of a 14 lb Earthbreaker (2d6).

So the real question is: what if my character wants to throw a 50 lb anvil? Or a 100 lb anvil (assuming he is strong enough to do so)? There are no weapons to compare this to as per the improvised weapon rules and we couldn't decide on what to do.

Basically, what I suggested was "re-skinning" the 10 lbs anvil to be a heavy flail (if wielded in melee with two hands, just no handle), and likewise a 14 lbs anvil would be like an earthbreaker, etc, and to treat them as such for throwing (with the "throw anything" feat). That got into the discussion above of items weighing much more being thrown by a character with sufficient strength, etc.

Come up with something on the fly that both rewards the player for creative thinking and doesn't completely negate the threat/encounter. The reason for the latter is to prevent the game devolving and so the spotlight doesn't shine too brightly on that player vs the rest of the table.

This is a huge part of the essence of a good GM.

Improvise. Adapt. Ensure focus is shared.

In a RotRL game, the GM lets us use fluff and flavor pretty freely. So my monk does an unarmed strike against a skeleton, and for flavor, the GM let me grab the skeleton by the sternum and smash it into an adjacent wall. Same amount of damage, still bludgeoning, didn't change the square it was in...but much more fun!

In a RotRL game, the GM lets us use fluff and flavor pretty freely. So my monk does an unarmed strike against a skeleton, and for flavor, the GM let me grab the skeleton by the sternum and smash it into an adjacent wall. Same amount of damage, still bludgeoning, didn't change the square it was in...but much more fun!

Yea, that's the kind of reskinning I suggested at first too, until the conversation went "bigger" than things of similar dimensions/mechanics of handheld things :)

In my view there should be only a single simple rule

Improvised weapons are improvised - as such they are always inferior to real weapons.

So equating damage with weight is dangerous. Large weapons have double weight of normal sized ones - but the damage doesn't scale equally.

A heavy crossbow thrown isn't as good as a dedicated weapon of the same weight. A heavy shield steel isn't making most damage because it is the heaviest weapon I could find with a quick browse.

Edit: changed is to should - the above is my personal opinion

About the anvil - I would see it closer to a throwing shield (10-15 pounds for a heavy shield) which is doing 1d6 damage. Maybe a very heavy anvil could get close to 1d10.

I once had a player throwing a full barrel. 'Throw' is relative - the poor goblin hit was directly in front and the character was looting the barrel and did have it on his shoulder. It made a memorable encounter as he rolled a crit. actually he truly had it on his shoulder as I use 3d materials and it just fitted on his miniature.

But he knew - despite the weight - it was inferior to his sword. He used it because dropping the barrel (free action), drawing the sword instead and use it seemed not the right thing to do. And I congratulate him.

But the danger here is if some 'rules' are done that suddenly characters walk around with heavy anvils as they just become better weapons as anything in the book.

Definitely downscale the weapon damage. Improvised weapons are unwieldy, and while it's obvious in the attack penalty, it's more subtle to notice in the damage. A flail concentrates the built up momentum and force into a single point of contact. An anvil is bulkier and less easy to find a point of easy contact. Also, consider how you're holding it. Can you swing it in such a way that you won't crush your fingers against the fighter's full plate? Can you put the full force of your strength into swinging the 50 pound anvil and not be spun around by the momentum? How do those factors express themselves in the damage? Weight isn't to sole factor of damage, but also the sheer dangerous nature of a weapon.

Also, consider how you're holding it. Can you swing it in such a way that you won't crush your fingers against the fighter's full plate? Can you put the full force of your strength into swinging the 50 pound anvil and not be spun around by the momentum? How do those factors express themselves in the damage?

We were thinking of this in the context of a character throwing said anvil (with the Throw Anything feat), which is why we were thinking of it more in terms of pure mass hitting someone directly and less of how good it is to use as a melee weapon.

About the anvil - I would see it closer to a throwing shield (10-15 pounds for a heavy shield) which is doing 1d6 damage. Maybe a very heavy anvil could get close to 1d10.

I once had a player throwing a full barrel. 'Throw' is relative - the poor goblin hit was directly in front and the character was looting the barrel and did have it on his shoulder. It made a memorable encounter as he rolled a crit. actually he truly had it on his shoulder as I use 3d materials and it just fitted on his miniature.

But he knew - despite the weight - it was inferior to his sword. He used it because dropping the barrel (free action), drawing the sword instead and use it seemed not the right thing to do. And I congratulate him.

But the danger here is if some 'rules' are done that suddenly characters walk around with heavy anvils as they just become better weapons as anything in the book.

That seems like a brilliant use of the surprise round. "Hm...I can draw my weapon and get ready for next round...or I can throw this heavy thing that I need to let go of anyway and draw my weapon next round.!"