Climate-change Blade?

[TheSalletSlayer]

So I'm running my first pathfinder game, and I wanted to introduce a few magic items to the campaign. One I had in mind was a sword that changes shape/size based on the temperature like mercury, so in an average temperate climate it is a regular short-sword (or longsword) but in a cold climate the blade would take the shape of a dagger, while in a hot environment it takes the shape of a longsword (or bastard sword). Ive read up on the transformative special ability and greater transformative I just want to see if maybe there is another alternative or other abilities that could achieve that effect.

[ArmchairDM]

Not aware of any other similar abilities. However, one of the great things about being a GM is you get to just make stuff up =) You don't have to give your new weapon one of the predefined properties.

In my own campaign if the players want to create an item I use the tables as guidelines for them but if I am personally creating an item for the campaign I don't even look at them. I just decide what I want it to do and give it a name and go with it.

[Imbicatus]

One thing to be aware of is that a weapon that changes type based on environment is mostly useless. Pathfinder rewards specialization, so a most characters focus on a single weapon. If the weapon is not what they invested feats in, then it will usually be passed over, because they will have wasted those feats and abilities if they do. If I make a great swordsman, and my main weapon turns into a dagger when it gets cold out, I'm going to just use a normal sword and sell the magic bauble.

[Pizza Lord]

Everyone knows that Climate-change Blade is a myth.

OneGiantDread wrote:

One I had in mind was a sword that changes shape/size based on the temperature like mercury,

We could call it a 'mercurial longsword'... Wait. No we can't. That's been done. Theoretically a sword with a channel of mercury in it so when you swing it concentrates at the tip and theoretically increases the force of the blow.

Like ArmchairDM says, there's nothing stopping you from making a weapon that does that. It's pretty straight-forward and easy enough to understand. Obviously most people wouldn't want to be in the cold, it would do less damage.

Imbicatus wrote:

Pathfinder rewards specialization, so a most characters focus on a single weapon.

This is important to consider. If you want this to not be an issue, just say that it's always as easy to wield as [longsword/shortsword/ whatever]. Or make it similar to how a sun blade works, where either proficiency counts.

Obviously if you do want to make it an issue... you'll find wielders reluctant to leave environments where their specialization lies (daggers, long swords, great swords, etc.)

It will take a good story/plan to make the item more than just a gimmick though (and if the adventure is just in one environment, who's ever gonna really know.)

Then account for localized effects. Is the blade strictly affected by the environment or can sticking it in a campfire for a minute or two affect it? If the wielder rolls a 1 and it takes damage from a fireball? Can a heat metal or chill metal change it for the duration?