The Stone of Recall is an item introduced in Diablo III that replaced the old Town Portal mechanic from the earlier games. It was removed during development and replaced with the ability to cast a Town Portal directly from the action bar. Originally, each player got their own personal Stone of Recall as a reward for completing the A Shattered Crown quest in Act I. Upon using the stone, the player was teleported back to town and a portal was left open from the location it was used, so the player could conveniently return back. The Stone of Recall had a 10 second cast time and could not be traded to other players nor did it take up inventory space.[1]
Originally Blizzard stated that they wanted to prevent players from opening a town portal during combat to go back to town and buy potions.[2]