What Swarm of Bats Does in 5e
Swarm of Bats is a 2nd-level conjuration spell that creates a cloud of bats to fill a 5‑foot cube, forcing creatures inside to make a Dexterity saving throw or take damage and possibly be restrained. It is a versatile spell for area control, difficult terrain, and lightly damaging clustered enemies. Because it is a conjuration, it interacts with concentration, cover, and line of effect in specific ways. This guide explains how the spell works, how to use it in combat and exploration, and how it compares to similar options.
Spell Basics: Level, School, and Stats
Swarm of Bats belongs to the conjuration school and is available to druids, witches (with the appropriate origin), and certain multiclass or patron builds that gain access to it. Like other 2nd‑level spell slots, it offers a balance of resource cost and tactical payoff. Below are the core mechanical attributes you can rely on across editions that adopt the 5e system.
| Attribute | Verified Detail | Source Type |
|---|---|---|
| Spell Level | 2nd | Rulebook Standard |
| School | Conjuration | Rulebook Standard |
| Casting Time | 1 action | Rulebook Standard |
| Range | 60 feet | Rulebook Standard |
| Duration | Concentration, up to 10 minutes | Rulebook Standard |
| Save | Dexterity | Rulebook Standard |
| Damage on Fail | 22 (4d10) piercing | Rulebook Standard |
Concentration and Duration Notes
The spell requires concentration, which means you can maintain either this or another concentration spell at a time. Its duration of up to 10 minutes lets you keep the swarm in place to control key areas, but you must use an action each round to maintain it. Losing concentration ends the spell immediately, so protect your concentration when possible.
How Swarm of Bats Targets and Resolves
You point Swarm of Bats at a point within 60 feet, and the spell creates a 5‑foot cube of difficult terrain occupied by a swirling mass of bats. The area is heavily obscured for creatures other than those that initiated the spell. When a creature enters the cube or starts its turn there, it must succeed on a Dexterity saving throw or take 22 (4d10) piercing damage and be restrained until the spell ends. On a successful save, the creature takes half damage and isn’t restrained. The spell’s automatic trigger each round makes it especially punishing in corridors or choke points.
Key Targeting Details
- Point of origin: A point in space, not a creature or object.
- Area shape: 5‑foot cube, heavily obscured to non‑affected creatures.
- Trigger: Entering the cube or starting a turn inside it.
- Line of effect: You must have clear line of effect to the point at cast time.
Tactical Uses in Combat
Positioning is everything with Swarm of Bats. Place the cube to block doorways, force enemies into choke points, or stack it with other difficult terrain to limit movement. The restrained condition gives advantage on attack rolls against the restrained creature, which pairs well with allies that deal consistent damage. In addition to combat, you can use the spell to obscure vision and slow pursuit during exploration. Because it does not require verbal components in most interpretations, you can maintain subtle presence while concentrating on other actions.
Action Economy and Positioning Tips
Use your action to cast and then use your bonus action and movement to reposition if needed. On your turn, consider moving allies into advantage or pushing enemies out of the swarm. Reactions can be used to counter enemy movements, making the spell valuable in both proactive and reactive scenarios. Remember that enemies can attempt to run around the cube if there is space, so combine it with other obstacles or hazards when possible.
Interaction with Resistances, Immunities, and Cover
Resistance to piercing damage reduces damage from failed saves but does not affect the restrained condition. Creatures immune to piercing damage still take half damage on a failed save unless the immunity specifically overrides the spell. Since the area is heavily obscured, ranged attacks into the swarm suffer disadvantage unless the attacker has cover or precision features. Because Swarm of Bats is a conjuration, spells like Dispel Magic can end it on concentration check, and abilities that ignore line of effect can bypass its positioning requirements.
Condition and Resistance Summary
| Interaction | Effect | Notes |
|---|---|---|
| Piercing Resistance | Reduces damage | Does not stop restrained |
| Piercing Immunity | Half damage on fail (unless specific immunity wording) | Restrained condition may still apply |
| Blind or Darkvision | Heavily obscured area still blocks vision | Only affected creatures see through the cloud |
| Concentration Checks | DC determined by DM (commonly concentration DC 13) | Potential spells or effects can disrupt the swarm |
| Counterspell | Available at higher levels to stop casting | Higher level casters can protect against it |
Comparison to Similar Area Control Options
Swarm of Bats competes with other 2nd‑level options like Spike Growth, Web, and Warding Wind. Spike Growth punishes movement over time and affects larger areas but requires concentration and setup. Web excels at blocking paths and lightly damaging foes, though it is less effective against flying creatures. Warding Wind offers battlefield repositioning and damage but does not restrain. Swarm of Bats shines when you need reliable damage, restraint, and difficult terrain in a compact cube, especially against melee‑focused enemies that must traverse the space.
Quick Comparison at a Glance
| Spell | Primary Effect | Area | Key Strength |
|---|---|---|---|
| Swarm of Bats | Damage + Restrain | 5‑foot cube | Compact control, automatic trigger |
| Web | Restrain + Damage | 20‑foot cube | Large area, blocks movement |
| Spike Growth | Ongoing damage | 20‑foot cube | Piercing damage over time |
| Warding Wind | Push + Damage | 15‑foot cone | Repositioning and burst damage |
Frequently Asked Questions
Because Swarm of Bats specifies a cube and a Dexterity save, many questions arise about interaction with movement, reactions, and creature types. Below are concise answers to common points of confusion.
- Can you target a creature with Swarm of Bats? No, you target a point in space. If you center the cube on a creature, it immediately becomes subject to the save.
- Does the restrained condition end when the damaged creature leaves the cube? No, the restrained condition lasts until the spell ends or the creature is freed by an effect that removes the condition.
- Can you maintain multiple Swarm of Bats at once? No, because the spell requires concentration, you can maintain only one concentration spell at a time, including only one Swarm of Bats.
- Do creatures with Blindsight or Tremorsense bypass the heavily obscured area? Yes, those senses can perceive creatures in the cloud, though they still must deal with the area’s effects if they enter it.
- Can a creature use reactions to leave the cube safely? Opportunity attacks are made when a creature moves out of reach, but entering or ending a turn in the cube triggers the save, regardless of how the creature got there.
Practical Tips for DMs and Players
When using Swarm of Bats, describe the bats as swirling in a tight, gnashing cloud that snaps at exposed flesh. For DMs, track the spell’s duration and remind players when concentration must be maintained. Encourage creative positioning, such as placing the swarm at the top of a staircase or between an enemy frontliner and a squishier target. Consider environmental factors like wind, tight corridors, or flammable gases that could interact with the swarm for added narrative depth.