Trigger shield

A creature of your choice that you can see within range is surrounded by protective magical force. The target gains temporary hit points, in the form of a magical shield, equal to 1d6 + your spellcasting ability modifier for the duration.

 If a creature hits the target with a melee attack and does damage that breaks the shield, the creature must make a constitution saving throw. The creature's speed is reduced by 20 feet until the start of your next turn and it takes force damage equal to the shielded amount on a failed save, on a save it takes half as much damage and its speed isn't reduced.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the temporary hit points and the force damage increases by 1d6 for each slot level above 1st.