From: Physics- why not?

[treellama]

Well...that'll teach me to trust documentation.

The MML might work for player -> monster projectiles. It was added before net games worked. Player -> player definitely requires a substantial Lua script, i.e. more than a few minutes' screwing around in Anvil or MML.

Irons wrote one, but realized pretty quickly how bad an idea it is. Learn from his mistakes.