Alarm 5E: DnD Spell Guide

There’s nothing like a good night’s sleep in an environment where you feel safe enough to forget the burdens of the day, relax your tired body, and truly rest. If you’re used to adventuring far away from the comforts of towns and their secure lodgings during a 5E campaign, such environments might even be considered a rare luxury not to be passed up when time allows.

The open road doesn’t have to be the enemy of a long rest, however. While it’s always a good idea to set a watch where possible, you can also establish additional security measures with magic before going to sleep – an easy task for even novice adventurers thanks to a simple 1st level spell.

In 5E, Alarm is a 1st level ritual spell that will quietly alert its caster or noisily alert nearby characters when an unknown creature touches or enters the warded door, window, or area. The spell also lasts for 8 hours, ensuring it will remain active through an entire long rest.

Adventurers sleeping in a tent
This is not where you want to be when a surprise battle breaks out.

DnD 5E Alarm Spell Description & Benefits

Now that we know the basics of how Alarm works in 5E, let’s take a closer look at the finer details and benefits this spell brings to the table.

1st level abjuration (ritual)

Casting Time: 1 minute
Range: 30 feet
Components: V, S, M (a tiny strip of white cloth)
Duration: 8 hours

You set an alarm against unwanted intrusion. Choose a door, a window, or an area within range that is no larger than a 20-foot cube. Until the spell ends, an alarm alerts you whenever a Tiny or larger creature touches or enters the warded area. When you cast the spell, you can designate creatures that won’t set off the alarm. You also choose whether the alarm is mental or audible.

A mental alarm alerts you with a ping in your mind if you are within 1 mile of the warded area. This ping awakens you if you are sleeping.

An audible alarm produces the sound of a hand bell for 10 seconds within 60 feet.

The Player’s Handbook, p.211

Benefit #1: Alarm is flexible enough for indoor and outdoor use.

A ward that is 20 feet long, wide, and tall (as per page 204 of the Player’s Handbook) covers a surprisingly large area, ensuring good coverage for small and large groups who are camping around a fire or in a cave through a single casting, regardless of most surrounding ledges or foliage in the area.

If you need to cover more ground than a single casting will allow, Alarm also isn’t tied to any concentration or other special casting limits, allowing you to make your coverage as large as your spell slots will allow.

You’ll still want to set a watch after your wards have been set up though, as attackers who use ranged weapons or spells can still get the drop on a campsite protected by an Alarm spell, but it’s a good second layer of defense against those using stealth, invisibility, plane shifting, or teleportation to show up unannounced.

When staying at a typical inn, however, it will quickly become impossible to sleep when the equivalent of a text message or phone call is constantly going off because your 20 foot cube overlapped into rooms above, below, or next to yours.

If you elected for the audible alarm when casting your spell, odds are your neighbors and owner of the inn won’t be appreciative of the noise either, and would be well within their rights to chastise you in whatever way they see fit. You only make that mistake once, let me tell you.

Fortunately, Alarm can also be bound to a single door or window of any size, so while it might take an extra casting or two to cover all possible entrance points, you’ll almost always be able to keep someone from getting the drop on you, even in the rougher parts of town.

Benefit #2: Alarm is a ritual spell.

While this benefit is of greatest note to artificers and wizards, as they are the only classes with inherent ritual casting that can learn the Alarm spell without jumping through extra hoops, any class that takes the Ritual Caster feat early on will get a lot of mileage out of a security spell that doesn’t cost spell slots.

To say nothing of the suite of other ritual spells you can learn over time from the wizard spell list. Well worth taking 10-30 minutes a night to set up as many alarm spells as you need to secure your sleeping arrangement.

Benefit #3: Alarm can be as loud or quiet as your party’s battle plan requires.

If you want the whole party to be roused when an intruder shows up and don’t mind alerting the enemy to the fact that they’ve been caught, the hand bell is a good way to avoid wasting early combat rounds rousing sleeping characters and ensuring your team is able to fight back in full numbers.

For those who want to turn the element of surprise back on a would-be assassin, however, the silent mental ping is a great way to ensure you have enough warning to either assess the situation, alert other party members quietly through sending stones or other silent communications, or simply make a loud attack that gets even the deepest sleepers out of bed.

Alarm bell
Subtle this isn’t, but it’s a lot easier to survive an unexpected attack if the whole party is awake.

5E Classes That Can Learn the Alarm Spell

Alarm can be picked up by a lot of different 5E classes, but most that are able to learn this spell without a feat must be part of a specific class archetype.

  • Artificer
  • Bard (Magical Secrets)
  • Fighter (Eldritch Knight)
  • Paladin (Oath of the Watchers)
  • Ranger
  • Rogue (Arcane Trickster, at 3rd, 8th, 14th, or 20th level)
  • Sorcerer (Clockwork Soul)
  • Warlock (Pact of the Tome + Book of Ancient Secrets)
  • Wizard

While it makes complete sense in terms of both mechanics and flavor for Alarm to be on the artificer, ranger, and wizard spell lists, it is admittedly surprising that such a useful adventuring spell isn’t more widely available.

Security is usually a priority for all but the most cocky adventurers, especially during times when they will be vulnerable, such as when they are sleeping. Not having ready access to a spell that will ensure you are awake to defend yourself from common threats feels like a pretty major oversight in 5E’s adventuring culture.

Further, the hoops other classes have to jump through in order to learn the Alarm spell are wildly inconsistent, meaning that many who can theoretically learn this spell have to make incredible sacrifices to do so, making it an unwise decision in most circumstances.

So who should and should not put this spell on their spell list? Let’s do a quick breakdown and see!

5E Classes Who Should Learn or Prepare the Alarm Spell


Artificers have access to ritual casting for spells that they have prepared, and with a 16 Intelligence, they can start with 4. Since you start out only being able to cast 2 1st level spells per day, dedicating 1 or 2 prepared spells to ritual slots is a great use of spell preparation at low levels, and is usually trivial to maintain as you level and gain the ability to prepare more spells per day.

Paladin (Oath of the Watchers)

A paladin who has taken the Oath of the Watchers will always have Alarm prepared as it is an oath spell for this archetype. While most paladin spell slots tend to be dedicated to smiting spells or abilities, if you have a 1st level spell slot left at the end of the day, Alarm is a great use for it to make it a bit safer for your party to rest.

Sorcerer (Clockwork Soul)

As with the paladin following the Oath of the Watchers, a Clockwork Soul sorcerer gains access to the Alarm spell as part of their class archetype, so they can always have it on hand without impacting the other spells they know. While you won’t always have access to a 1st level spell slot after a day of adventuring, Alarm can definitely help you sleep a little more soundly on the days you do.

You can also elect to swap Alarm out for a different 1st level abjuration or transmutation spell from the warlock, wizard, or sorcerer spell lists, but most in the Player’s HandbookXanathar’s Guide to Everything, and Tasha’s Cauldron of Everything that you don’t already have access to from the sorcerer’s spell list simply aren’t worth the trade.

Warlock (Pact of the Tome + Book of Ancient Secrets)

A warlock’s Book of Ancient Secrets is absurdly powerful because it grants them access to every ritual spell in the game. If you elect to take different 1st level ritual spells when learning this Eldritch Invocation, you will spend a maximum of 100 gold buying an Alarm scroll and inscribing it into your book, which is a great deal for unlimited access to a quality security spell.


As with the warlock’s Book of Ancient Secrets, you can easily elect to either learn the Alarm spell or spend up to 100 gold adding it to your spellbook for unlimited use thanks to a wizard’s built in ability to cast wizard spells with the ritual tag as rituals without expending spell slots. Well worth an early investment, regardless of your archetype.

Anyone who takes the Ritual Caster (wizard list) feat

The Ritual Caster feat allows any character to carry a repository of useful utility spells whose only limitation is a 10 minute casting time. Wizards have a great selection of ritual spells to work with, and since 1st level spell scrolls are common, it should be easy to locate one with the Alarm spell that you can scribe if you elected not to start with access to Alarm.

witch casting ritual spell
Nothing’s sneaking up on her during the night!

5E characters that should always learn the Alarm spell:

  • Artificers
  • Paladins (Oath of the Watchers)
  • Sorcerers (Clockwork Soul)
  • Warlocks (Pact of the Tome + Book of Ancient Secrets)
  • Wizard
  • Characters with the Ritual Caster feat (wizard spells)

5E Classes Who Should Never Learn or Prepare the Alarm Spell

Bard (Magical Secrets)

The Magical Secrets class feature is available to all bards at 10th, 14th, and 18th level, and if you’re part of the College of Lore, you also receive access to it at 6th level. Using it, you can learn spells from any class, making access to Alarm simply a matter of time.

Don’t use this class feature on Alarm.

While a great 1st level spell that compares very favorably with many of its 1st level peers, Alarm just doesn’t hold a candle to the best 2nd and 3rd level spells across all classes at 6th level, let alone the powerful options 4th level magic and above brings to the table. Banishment, Fireball, Fly, Plant Growth, Spider Climb – the list of better spell selections could go on for some time.

Fighter (Eldritch Knight)

Alarm is an abjuration spell, so Eldritch Knights can learn it without issue, and it’s useful enough that it can be valuable despite being learned at 3rd level. Unfortunately, Eldritch Knights are third casters who learn very few spells (13 at 20th level), and their class features are set up to promote an attack pattern that utilizes attack spells requiring saving throws.

Worse, despite drawing from the wizard spell list for the spells they can learn, Eldritch Knights do not gain access to a wizard’s inherent ritual casting capability, so you’ll have to hold back a precious spell slot if you want to use Alarm at the end of the day, and you accumulate those more slowly than all other spellcasters apart from the Arcane Trickster.


Rangers, despite being half casters, are more stunted in terms of spells they get to know than even third casters, having access to a mere 11 at 20th level. As if that wasn’t enough, Alarm has to compete against the likes of Absorb Elements, Detect Magic, Entangle, Hail of Thorns, and Hunter’s Mark.

Leave Alarm to the wizard or ritual caster in your party and don’t look back.

Rogue (Arcane Trickster)

While Alarm is admittedly much more useful to a rogue than a fighter, as they’re generally more prone to making enemies with the means to hire assassins, Alarm isn’t an illusion or enchantment spell, meaning you have to spend one of your 4 precious spell selections outside of these schools on Alarm if you want it.

The only time I would consider this worthwhile is at 3rd level, as you can gain access to far better spells with your 8th, 14th, and 20th level selections, and even then, worthwhile is a very relative term once ritual casting is out of the picture. There are many stronger choices available on the wizard spell list – take one of those instead of Alarm unless you’re really paranoid.

5E characters who cannot or should not learn or prepare the Alarm Spell:

Is the 5E Alarm Spell Worth It?

Alarm is a very worthwhile spell when you don’t have to go out of your way to accommodate it. Ritual spellcasting via your class or the Ritual Caster feat is the absolute best way to use this security spell, as you can protect your camp or room without having to spend spell slots doing so.

Class archetypes that have access to the Alarm spell for free like the paladin’s Oath of the Watchers or the sorcerer’s Clockwork Soul are also able to get solid mileage out of this 1st level spell as long as they weren’t taxed to their spellcasting limits earlier in the day.

Beyond these cases, Alarm starts to become a questionable pick for the classes that can learn it. While there are a lot of 1st level spells that are considered far worse than Alarm, there are also quite a few that are considered far better once you are allocating the spell slots and spells known for your class.

If your DM likes to randomly roll to see if an encounter disrupts the party’s sleep at night, Alarm is a perfect shield against surprise rounds from wild beasts and melee combatants looking for free attacks on your sleeping party members. If this isn’t a common fixture of your campaigns or your adversaries tend to favor ranged combat, Alarm isn’t going to offer much protection.

Only one person really needs to have this spell for it to achieve its peak usefulness as well, so if another party member has easy access to the Alarm spell, let them take point on collecting it so you can learn and prepare spells that will give you more coverage in a fight or a solution to common problems that crop up when exploring a dungeon.

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