17 Feb Sleep 5e D&D Guide 
A classic, the Sleep spell has been around as long as the game itself. It is an ultimate crowd control spell at lower levels and can turn a battle in the players’ favor with one cast.
The rules for Sleep can be found in the Players Handbook on page 276.
Enchantment 1st level
Casting Time: 1 Action
Range: 90 feet
Components: V, S, M (A pinch of fine sand, rose petals, or a cricket)
Duration: 1 minute
This spell sends creatures into a magical slumber. Roll 5d8, the total is how many hit points of creatures this spell can affect. Creatures within 20 feet of a point you choose within range are affected in ascending order of their current hit points (ignoring unconscious creatures).
Starting with the creature that has the lowest current hit points, each creature affected by this spell falls unconscious until the spell ends, the sleeper takes damage, or someone uses an action to shake or slap the sleeper awake.
Subtract each creature’s hit points from the total before moving on to the creature with the next lowest hit points. A creature’s hit points must be equal to or less than the remaining total for that creature to be affected. Undead and creatures immune to being charmed aren’t affected by this spell.
At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, roll an additional 2d8 for each slot level above 1st.
The rules for Sleep indicate that it is excellent crowd control, best used on small enemies. It does have the option to be up-cast, however, the number of creatures affected is still variable based on the die roll. This can make sleep a very risky play.
Is Sleep Good?
Sleep is the ultimate crowd control spell at low levels. This is based on the concept that the enemies earlier on have significantly fewerhit points per creature. The average hit points affected roll is slightly above 20. This equates to multiple smaller enemies such rats, kobolds, goblins, and wolves succumbing to its effects.
It is generally safe to use around your allies as well since it starts affecting the lowest amount of hit points first. Your allies will still go down, but they should be some of the last creatures impacted and don’t take any damage. An action can be used to wake them up if they do go down.
At higher levels, there is still an opportunity to use the spell since it has a range and the ability to be up-cast. The total on the die roll plays a significant part in how effective it will be each cast and leaves a lot to chance.However, when it does work, a good roll on an upcast sleep spell can buy some much-needed time for healing or a hasty escape.
How Does Sleep Work?
Rolling 5d8 gives you a total amount of hit points that can be affected by the spell that are in the 20 ft range. Starting with the lowest hit point, creature in the zone subtract their hit points from the total, and they fall asleep. Leftovers are lost and have no effect.
The wizard casts sleep. He rolls 5d8 and comes up with 24. The 20-foot radius gets six kobolds and his ally, who is a fighter. Each kobold has 5 hit points, and the fighter has 12 hit points. Starting with kobold one, he subtracts 5 hit points from the 24-hit point total. This affects 5 kobolds for a total of 20 leaving 4 hit points left over. The last kobold has 5 hit points, which is greater than the 4 remaining points, so he is unaffected. The fighter is also above the remaining hit points, so he is also unaffected.
What Classes get Sleep?
Sleep is available to three main classes – the Bard, Sorcerer, and Wizard. It is also available to numerous subclasses -the Eldritch Knight, Arcane Trickster, Twilight Cleric, Redemption Paladin, and the Archfey Warlock. The Dimir Guild of Ravnica and The Dragonmark: Mark of Hospitality also have the spell available.
What Conditions are Caused by Sleep
The Sleep spell is a charm spell and should be treated as such. Creatures immune to charm such as undead cannot be affected by this spell. A sleeping creature is unconscious. Unconscious creatures are incapacitated.
They also drop anything they are holding and fall prone. These creatures automatically fail strength and dexterity-based saving throws. Attack rolls have advantage against these creatures. Also, any hit from an attacker within 5 feet is a critical hit.
Creatures that are immune to charm are completely immune to sleep which does make it a little more situational. The bread and butter of crowd control spells that don’t differentiate between friend and foe, Sleep is a fun way to create some chaos without doing any damage to friends.