Alter Self, Projectiles, and Size changes.

[Markov Spiked Chain]

Enlarge Person and Reduce person have contradictory rules on how size changes affect projectiles:

Reduce Person wrote:

This means that thrown weapons deal their normal damage (projectiles deal damage based on the size of the weapon that fired them).

Enlarge Person wrote:

Any enlarged item that leaves an enlarged creature's possession (including a projectile or thrown weapon) instantly returns to its normal size. This means that thrown and projectile weapons deal their normal damage.

Which I suppose is fine to just work differently, but how do other size changes work?

Specifically, if I'm a Human and I Alter Self into a Halfling (small size), how much damage does my longbow do? Is it different if I'm a Halfling who Alter Self's into a Human (one follows Reduce Person, one follows Enlarge Person?)

[Cevah]

The size of objects revert when they leave your hold. They don't change speed or direction.
There should be no difference between thrown weapons and projectiles, as the power that threw them was reduced/enlarged the same amount by the spell. They should be treated the same. They are.

The parenthetical under Reduce Person just states the normal damage rules for projectiles. That is, "projectiles deal normal damage also".

The problem is not there, but rather the fact that the inertia of the object magically increased/decreased, and is not accounted for in the size change. To simulate this correctly would involve a lot of theory to get the correct formula, so instead they handwave it to use the normal size for the object to determine damage.

The way to make good use of this is to get an efficient quiver and load up on large arrows in the javelin slot. [Max 18 large arrows.] Then when you are enlarged, either temporarily remove the quiver or briefly let go of each arrow to allow it to revert to normal. Then shoot with the large bow for extra damage.

/cevah