Contingency Teleport

When you cast this spell you must select a position in your line of sight and within 30ft. For the next minute if you would be damaged by a successful attack against you, you will be teleported the moment before the damage would be inflicted, you will then appear in the space you designated at the casting of this spell.

This spell considers any effect that forces you to roll a saving throw to avoid or if a roll was made against your armour class, as an attack. Regardless of the source or whether or not you were the intended target. The spell responds to the certainty of damage. 

Once this spell is triggered or when the time elapses the spell ends.