How much damage does a collapsible bathtub do

damageimprovised-weaponrypathfinder-1e

So the title asks it all – I have a bit of backstory if your interested into why I want to know how much damage a collapsible bathtub does it doesn't really mater but I'm curious as to people's thoughts on this manner

I'm currently playing an unchained summoner (story summoner archetype), and happen to have chosen an eidolon which has high strength and no weapon proficiency. Due to the fact that its natural attacks just fail against something that has protection from [current alignment] I wanted the ability to have a weapon, due to unchained my evolution points are fairly limited and I honestly would like to avoid spending 4 of them for a decent weapon proficiency and if I have to spend a feat I'ld rather spend one on making it's attacks far more interesting… so I am now asking how much damage does a collapsible bathtub do?

RAW

"To determine the size category and appropriate damage for an improvised weapon, compare its
relative size and damage potential to the weapon list to find a reasonable match. An improvised weapon scores a threat on a natural roll of 20 and deals double damage on a critical hit. An improvised thrown weapon has a range increment of 10 feet."

I have an idea of what it should do – but I'm not posting that as it might bias what you guys think about this rather silly weapon's damage die

Best Answer

Probably 1d10 bludgeoning damage at best for a bathtub sized for a medium creature

A collapsible bathtub is a big and cumbersome weapon that is difficult to swing. In that sense, it is essentially a rather unorthodox greatclub - a two-handed weapon that deals 1d10 bludgeoning damage. This assumes your eidolon is medium and the bathtub is appropriately sized for being wielded by medium creatures (ie, its more of a child sized tub). A larger bathtub would deal more damage following the typical weapon size rules.

Note that if the bathtub was not appropriately sized for the creature wielding it (ie. if you wanted to argue that it should deal more damage because its sized for a creature bigger than your eidolon), your eidolon would no longer be able to wield it due to the CRB equipment rules for weapon sizes.

The measure of how much effort it takes to use a weapon (whether the weapon is designated as a light, one-handed, or two-handed weapon for a particular wielder) is altered by one step for each size category of difference between the wielder’s size and the size of the creature for which the weapon was designed. For example, a Small creature would wield a Medium one-handed weapon as a two-handed weapon. If a weapon’s designation would be changed to something other than light, one-handed, or two-handed by this alteration, the creature can’t wield the weapon at all.

As an alternative to the logic above, the Improvised Weapon Mastery feat also provides an upper end to the range for improvised weapon damage.

Benefit: You do not suffer any penalties for using an improvised weapon. Increase the amount of damage dealt by the improvised weapon by one step (for example, 1d4 becomes 1d6) to a maximum of 1d8 (2d6 if the improvised weapon is two-handed). The improvised weapon has a critical threat range of 19–20, with a critical multiplier of ×2.

This implies that the highest damage an improvised weapon should be dealing is 2d6, and only once you have the feat.