Warlock Punch

Your Fist is empowered with eldritch energy. Make a melee spell attack against the target. On a hit, the target takes 1d12 force damage.  The target makes a strength saving throw. On success nothing else occurs, on failure the target is pushed back 5 ft.

This spell's damage increases by 1d12 and the distance pushed increases by 5 ft when you reach 5th level (2d12, 10 ft), 11th level (3d12, 15 ft), and 17th level (4d12, 20 ft).