The following material is Open Game Content from a 3PP Source
Undead Warding: Three times per day, the bearer of a shield with this ability can create a shimmering golden dome of 5 ft. radius. Undead creatures are unable to physically enter the dome, though they can still attack you with ranged weapons or targeted spells. Living creatures (friend and foe alike) and constructs can enter the dome without problem. The dome will remain in existence for 7 rounds. Any attempt to move at more than half your normal speed, or to take more than a single attack, while the dome is active will end the effect.