Retention Barrier forms a 10-foot hemisphere where creatures can enter freely but cannot exit due to an invisible barrier similar to a wall of force.
No physical or spell attacks can cross it. A disintegrate spell destroys the barrier, but teleportation allows escape.
As you advance, an unseen dome envelops you within a 10-foot space. Though invisible, it blocks all escape and attacks. Only teleportation or disintegration can penetrate this intangible barrier.