All sorts of bad behavior can occur if we start letting people teleport to adjacent tiles (not the true destination) from one subserver to another. There are, and have been, plenty of problems caused just by invalidating the original destination in the first place. The server can *very* easily find an adjacent, good tile. All it does is verify that there’s valid terrain, and nothing that blocks movement (mobs or heavy items) on the tile. But is it a house step, or, heaven forbid, *inside* someone’s house? Is it one tile past a secure border players aren’t meant to pass? Is it cut off from other tiles (an island)? The questions go on, as does the potential for exploits, and thus, the reasoning for linking directly to the known-good tile from casting “Mark.”

-Draconi

To read more, go here.