Forceful Spellcasting

When you cast a spell that causes forced movement of another creature (ex. Thunderwave) increase the distance the creature is moved based on the level of the spell. A spell cast at a higher level is treated as that level for purposes of the distance added. In addition if the movement is ended early due to such features as walls, large rocks, or other impediments as determined by your GM the creature takes 1d4 points of bludgeoning damage for each 10ft of movement that was prevented. 

Cantrips - 1st level spells: +5ft

2nd-3rd level spells: +10ft

4th-5th level spells: +15ft

6th-7th level spells: +20ft

8th-9th level spells: +30ft