Ward Against Undead

When you cast this spell, choose a 10-foot radius or 30-foot radius. A radiant barrier extends out from you in all directions, filling its area with bright light out to 30 feet beyond the barrier. The 30-foot radius barrier is immobile, while the 10-foot radius barrier moves with you. Undead creatures cannot physically enter the warded area unless they roll a successful Wisdom saving throw. Those hedged out can still use spells or weapons to reach targets targets within it.

Undead creatures already within the area when it is created or those who enter the area due to your movement have their speed reduced by half while within the area.

At Higher Levels. If you cast this spell using a spell slot of 5th level or higher, undead creatures roll the saving throw with disadvantage. If you use a spell slot of 7th level or higher, no save is allowed.

Adapted from the AD&D 2nd edition book Pages From The Mages.