Barrier

You create a thin, shimmering wall of energy on a surface you can see within range. You can form it into a hemispherical dome or sphere with a diameter of up to 10 feet, or a wall up to 20 feet tall and 20 feet long. The wall can be straight or curved. Creatures can move freely through the barrier, but one side of the barrier which you choose when you cast the spell gives half cover to creatures standing behind it.

At Higher Levels. When you cast this spell using a spell slot 2nd level or higher, you can make the wall up to 10 feet higher and longer for each level above 1st.