Blink is a level 3 transmutation spell. This spell allows the spellcaster to travel to the Ethereal Plane, becoming temporarily unassailable and unseen until they return.
Description
Available only in combat.
At the end of your turn, roll a d20. On 11 or higher, you vanish into the Ethereal Plane. While there, you can't be harmed or seen in this world.
When you do vanish, your presence here is a representation of the location you'll come back to. You can choose to teleport it up to 6 m / 20 ft.
Properties
Details
Range: Self
At higher levels
Upcast: Casting this spell at a higher level doesn't grant any additional benefits.
At the end of each turn, there is a chance the affected entity gets Blinked to the Ethereal Plane, where it can't be harmed, seen or affected.
While in the Ethereal Plane, the entity can't move or interact with anything in the world. It can only choose to teleport up to 6 m / 20 ft. When combat ends, so does this effect.
d20. On 11 or higher, you vanish into the Ethereal Plane. While there, you can't be harmed or seen in this world.
6 m / 20 ft.
Duration: 10 turns 
, where it can't be harmed, seen or affected.
Ring of Blink 
Recharge: Long rest
Blink on the Forgotten Realms Wiki