Blur

Level 2 Illusion spell available to Sorcerers and Wizards. Your outline shimmers and every Attack Roll against you has Disadvantage for ten turns. No save, no cleverness required, and it roughly halves the number of hits you take.

Spell description: Your body becomes blurred. Attackers have Disadvantage on Attack Rolls against you.

Spell properties

• Range: Self
• Duration: 10 turns
• Concentration spell
• Conditions applied: Disadvantage on Attack Rolls against you.
• Cost: Action + Spell Slot
• Recharge: Per action

Spell upcasting

Casting Blur at higher levels provides no additional benefits.

How to obtain Blur

• Sorcerer, Wizard at Class level 3

Source items: Cloak of Displacement, Shifting Corpus Ring, Scroll of Blur

When to cast Blur

Disadvantage is worth about 5 points off the attacker’s roll, and unlike Armour Class it does not care how enormous their bonus is. Against the Act 3 heavy hitters who clear 20 AC without blinking, Blur is doing more for you than any amount of armour.

The cost is Concentration, and that is the whole decision. A Wizard running Blur is not running Web, Hold Person, or Haste. If your caster’s job is control, Mirror Image gives you a comparable defence for free, and the two are not really competing spells so much as competing for your Concentration.

So Blur belongs on the caster who intends to stand in the fight and stay there: a sword-and-spell Wizard, an Eldritch Knight, a Sorcerer with nothing else worth concentrating on. Cast it before combat and most of the ten turns will still be there when the first arrow arrives.

The Cloak of Displacement does the same thing for free while you are undamaged, which is often the better route. Take the cloak, keep your Concentration.