Balanced Counterspell

You attempt to interrupt a creature in the process of casting a spell. If the creature is casting a spell of 3th level or lower, its spell fails and has no effect. If it is casting a spell of 4th level or higher, make an ability check using your spellcasting ability. The DC is equal to 16 + the spells level - 3. On a success, the creature's spell fails and has no effect. You cannot use this on a spell that has a casting time of a reaction.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the interrupted spell has no effect if its level is less than or equal to the level of the spell slot you used and the DC changes to 16 + the spells level - level of spell slot used.