Back-to-Back

     This feat can be acquired by any martial class that has reached 4th level, and has put in the requisite amount of training with a partner (length left to the DM's discretion).  The duo goes Back-to-Back and circumspects the terrain as they rotate within the ten foot sphere they occupy.  While they remain Back-to-Back the receive the following benefits:  All attack rolls, saving throws, and DC's are made at advantage; furthermore, no adversary can sneak up on them through non-magical means.  Otherwise, all damage rolls are rolled normally considering each PC's normal stats.