Efreets* are genies of fire, elemental beings akin to jinn, but more consistently wicked and malicious. They’re strong, cunning and ruthless, and they view mortal humanoids as lesser beings fit only for enslavement and other forms of exploitation.
With their extraordinarily high Strength and Constitution, they’re straight-up brute fighters. But not dumb ones: their Intelligence, Wisdom and Charisma are all high as well. They have proficiency in Wisdom saving throws, along with Intelligence and Charisma, but not in Dexterity or Constitution. Their native Constitution is so high, they needn’t worry about making Con saves, but their Dexterity is barely above average for a humanoid, so they’ll be slightly warier of spellcasters than jinn are.
In addition to a double scimitar attack that does both slashing damage and bonus fire damage with a ferocious +10 bonus to hit, efreets can also Hurl Flame, doing 5d6 fire damage at a range of up to 120 feet. (You can bet that spellcasters, with their lower average armor classes and ability to circumvent the efreet’s high AC, will be primary targets of this ability.) Both the attack modifier and damage of this ranged attack are lower than those of the efreet’s melee attack, so an efreet will Hurl Flame only when a particular ranged opponent is giving it more trouble than any of its melee opponents are—and, moreover, that ranged opponent is more than 60 feet away, out of range of the efreet’s flying movement. Within 60 feet, the efreet will simply rush the opponent and attack with its scimitar.
The efreet’s repertoire of spells is similar to the jinni’s. Like jinn, efreets can innately cast gaseous form, invisibility and plane shift once per day each, giving them ways of escaping when seriously injured (reduced to 80 hp or fewer); plane shift can be used offensively against a single foe as well. Conjure elemental can summon an ally whose tactics we’ve looked at already, and major image can create a distraction.
But one thing efreets have that jinn don’t is a single daily use of wall of fire, which does 5d8 fire damage per turn to all opponents within it or within 10 feet of one side of it. Since the wall is opaque, an efreet can use wall of fire to cut itself off from enemy spellcasters and ranged attackers; even better, it can also create a ring-shaped wall with a 20-foot diameter around itself, forcing melee opponents to take damage both from its scimitar and from the wall. It’s a Large creature with 200 hit points and a flaming scimitar, and it’s immune to the fire damage. “I’m not trapped in here with you—you’re trapped in here with me!”
Efreets can also cast enlarge/reduce up to three times per day. For very brief interactions, efreets can reduce themselves to Medium size, making themselves appear as nonthreatening as red-skinned fire devils possibly can, but the spell’s duration of just 1 minute indicates that this spell is really meant for combat, not social interaction. An efreet can’t keep this spell going for long periods of time in order to blend in with society. More likely, they’ll cast enlarge on themselves during combat for the additional 1d4 damage they gain with each weapon strike. The question is, when? The effect takes a full action, and the opportunity cost of that action is much greater than 2d4. Becoming a Huge creature rather than a Large creature offers limited advantages, but I can think of one off the top of my head: The target of a grappling attack can be no more than one size Larger than the attacker. Thus, any Medium-size player character crazy enough to try to grapple an efreet will find the task simply impossible once the efreet grows from Large to Huge. In short, an efreet will enlarge itself when Huge size allows it to avoid an attack or an effect that Large size doesn’t.
Efreets are clever and patient fighters who can outlast more fragile opponents and know it. If melee opponents are giving them trouble, they’ll Disengage (action) and fly into the air out of their attackers’ reach, repositioning themselves so that they can face all those opponents at once without being flanked. From the air, they can Hurl Flame to eliminate or suppress spellcasters and other ranged attackers so that they can then proceed to clobber their melee opponents without distraction.
Efreets don’t parley as readily as jinn do, and when they do, they always try to gain an edge or negotiate a loophole that will give them the better end of the bargain. Helping them further their interests in no way guarantees that they’ll be inclined to help the PCs further theirs. Efreets readily accept offers of surrender, but surrendering to an efreet invariably means becoming its thrall—and servitude to an efreet may well mean an unplanned sojourn of indefinite duration on the Elemental Plane of Fire.
* The Monster Manual uses the singular “efreeti” and plural “efreet,” apparently by analogy to singular “jinni” and plural “jinn,” but this is an error. It’s true that in Arabic, a single “genie” is called جنّي jinnī, and “genies” as a class are called جنّ jinn, but the singular word for a malicious, wily supernatural being is عفريت ˁifrīt, and the plural is عفاريت ˁafārīt. عفريتي ˁifrītī is an adjective meaning “fiendish.” Instead of “afarit,” I use the anglicized plural “efreets.” ^