Load the trebuchet with a phrase from your quiver — one of the three-word phrases only you have ever posted, finite ammo. Paste a post URL to launch a reply, type a handle to launch a strike at a poster (they'll see it crash into their view next time they sign in here), or leave it empty and lob it into the open as a standalone post. Either way it posts the phrase (with a card + a link to where you coined it) and spends it — used twice, it's no longer yours alone.