Improved Portal Alarm — Interplanar Gate Warning
Abjuration · Planar gate security · Supplemental spell
The portal watchman hears a bell only he can hear. Alongside the warning comes a vision: three armoured travellers and a figure cloaked in mist have passed through the gate. The image reveals the direction of passage, not the visitors’ intentions.
At a Glance
| Spell | Improved Portal Alarm (Portal Alarm, Improved) |
|---|---|
| Published source | Manual of the Planes; subsequently Spell Compendium |
| Legacy level | Bard 4; Sorcerer/Wizard 4 |
| Target | One interplanar gate or portal |
| Duration | 8 hours per caster level, dismissible |
| Warning | Mental, audible or both; mental notice includes a picture and direction of passage |
| Recipient | Caster or a separately designated creature touched by the caster |
| Focus | Small leather pouch holding three brass bells |
The Gate That Remembers
A regular portal alarm alerts a keeper that something crossed a particular planar gateway. The improved spell also helps identify what crossed. When mental notification is selected, the warning brings an image of the travellers and whether they entered or exited, from a vantage comparable to standing ten feet from the gate.
The warning is not continuous remote vision. The caster does not gain a permanent scrying screen or the right to follow travellers after their crossing. The spell is best used as an early-warning measure for a watched threshold, not as a substitute for pursuit or interrogation.
Choosing the Right Ward
| What the gatekeeper needs | Suitable magic | Important limit |
|---|---|---|
| Know that someone crossed a specific planar portal | Portal Alarm | Reports the crossing, not the traveller’s appearance or direction. |
| See who crossed, and which direction they travelled | Improved Portal Alarm | The mental image is a brief view of the crossing, not continuous remote sight. |
| Guard the approach to a gateway without a portal-specific spell | Alarm, placed on the nearby entrance or chamber | Detects entry into the warded area; it does not prove interplanar travel. |
What Is Happening Right Now?
The keeper of an old stone gate west of Milan sees three travellers in his mind. They have just crossed from the Fey World. One wears a stolen customs seal, another carries a wounded child, and the third has hidden her face. The ward shows their appearance and direction of travel, but neither guilt nor intention. The characters can follow the traces, protect the child or challenge the official who issued the seal before the trespassers vanish among the city’s caravans.
The spell has raised an alarm, not closed the passage. Any pursuer still needs a route, allies and a way to recognise the travellers if they change their clothing.
Rules by Edition
Improved Portal Alarm — D&D 2024
Not a published D&D 2024 spell.
Published local-ward alternative: Alarm, Level 1 Abjuration
Casting Time: 1 minute or Ritual
Range: 30 feet
Area: Door, window or a space no larger than a 20-foot Cube
Components: V, S, M (bell and silver wire)
Duration: 8 hours
The caster designates creatures that will not trigger the ward and chooses either an audible or mental warning. The audible notice rings for ten seconds within 60 feet of the area; the mental ping reaches the caster within one mile.
Example: A ranger wards a chamber containing a permanent planar door. A visitor who enters the chamber triggers the local Alarm unless exempt; however, the spell cannot display that visitor’s appearance or determine their direction of planar travel.
There is no published rule for converting a high-level slot into the legacy image-bearing, eight-hour-per-level portal ward. Do not describe 2024 Alarm as an identical spell.
Improved Portal Alarm — D&D 2014
Not a published D&D 2014 spell.
Published local-ward alternative: Alarm, 1st-level Abjuration (Ritual)
Casting Time: 1 minute
Range: 30 feet
Area: Door, window or a space no larger than a 20-foot cube
Components: V, S, M (a tiny bell and fine silver wire)
Duration: 8 hours
When a Tiny or larger creature enters or touches the warded area, the spell produces the chosen mental or audible warning unless that creature is exempt. The mental warning is limited to one mile; the audible handbell sounds for ten seconds within 60 feet.
Example: A mage sets Alarm in a gateway hall. When a traveller walks past the sentry, the warning sounds; the spell neither identifies the traveller nor provides a mental snapshot of activity on another plane.
It does not reproduce the original fourth-level Improved Portal Alarm’s long duration, cross-planar triggers or transferred visual notification.
Improved Portal Alarm — Pathfinder 1e
Optional adaptation of a published legacy D&D spell, not a Paizo core spell.
School: Abjuration
Suggested level: Bard 4; Sorcerer/Wizard 4
Casting Time: 1 standard action
Components: V, S, F (leather pouch with three brass bells)
Range: Close (25 ft. + 5 ft./2 caster levels)
Target: One interplanar gate or portal
Duration: 8 hours/caster level (D)
Saving Throw: None for the ward; Will negates when transferring notification to an unwilling creature
Spell Resistance: No for the ward
If approved for the campaign, ward one actual interplanar portal. A creature of Tiny size or larger crossing it triggers the ward unless it speaks the configured password. Ethereal and astral travellers passing through the portal are also eligible to trigger it. Choose audible, mental or both notification modes.
A mental notice reaches the intended recipient while within one mile and on the portal’s plane, and includes a brief image of those who passed and their direction of travel, with the perspective of an observer about ten feet away. The caster can designate another touched creature to receive it, subject to a Will save if that creature resists. An audible warning behaves as a conventional portal alarm; magical silence can suppress the sound.
Example: A level-10 sorcerer protects a planar gate for eighty hours. A trusted sentry receives the mental image of two beings leaving the portal; that sentry still must decide whether they are friend or foe.
Improved Portal Alarm — D&D 3.5e
Published supplemental spell, Spell Compendium (not D&D 3.5e SRD).
School: Abjuration
Level: Bard 4; Sorcerer/Wizard 4
Casting Time: 1 standard action
Components: V, S, F (small leather pouch containing three brass bells)
Range: Close (25 ft. + 5 ft./2 levels)
Target: One interplanar gate or portal
Duration: 8 hours/level (D)
Saving Throw: None for the portal ward; Will negates if applicable to the chosen notification recipient
Spell Resistance: No
Improved Portal Alarm incorporates the source spell Portal Alarm: a chosen interplanar gateway triggers an alert when a Tiny or larger creature passes through it. The caster may select mental, audible or simultaneous notices. The mental notice provides the appearance and direction of travel of the creatures crossing, viewed as though the recipient stood roughly ten feet from the portal.
The alarm’s basic modes still matter: mental notifications are available within one mile on the same plane, while the audible bell rings for a round and may be heard clearly to 60 feet or faintly farther away. A Silence effect may block the audible warning but not the mental one. The original password exception remains, and astral or ethereal passage through the portal can also trigger the effect.
The caster may touch another creature to make that creature the recipient of the mental warning. An unwilling creature can attempt the specified Will save to reject the transfer. This is a warning and recollection of a crossing, not a means of watching all events on both planes.
Example: A level-12 wizard sets the ward for ninety-six hours. A planar merchant who knows the password may cross silently, but unknown creatures crossing without it yield both an alarm and a visual report.
Playing the Gatekeeper
A powerful trading portal lies under the watch of a sentry who cannot abandon their post. The wizard passes the mental warning to that sentry, who must recognise a genuine threat from a procession of merchants, disguised travellers and refugees. A clear image of the travellers may be accurate while still concealing their intentions.
Adventure Hooks
Three Bells, No Witness
The portal sounded an alarm but no guard saw anyone emerge. Its keeper has a clear mental image of three soldiers leaving the threshold; none is recorded in the garrison’s muster rolls.
The Wrong Receiver
A traitor persuades the gatekeeper to transfer the mental alarm to a compromised guard. The portal still works, but the person receiving its most valuable information is now the enemy.
Return to the Empty Arch
Travellers appear to emerge from a closed gateway every night, although the portal itself is dormant by day. The party must investigate who is opening it, how often and from which plane.
Related Spell and Source
The shorter, second-level Portal Alarm is the source of this ward’s underlying triggers; the base spell is now published at Portal Alarm, with its original supplemental source documented here: Portal Alarm in Spell Compendium. For modern campaigns see D&D 2024 Alarm or D&D 2014 Alarm; these lack the portal-specific image and travel-direction powers. Planar Campaigns provides a broader setting for guarded crossings. Other security magic includes Magic Mouth for a spoken warning and Hold Portal for blocking an ordinary door—neither replaces this specific planar warning.
Source and Attribution
Original spell from Manual of the Planes (D&D 3.0), with a D&D 3.5e entry in Spell Compendium, page 160. These are supplemental published works; the spell is not identified as freely reusable SRD or Open Game Content. Its statistics and mechanics are summarised in original explanatory prose, not reproduced as a full source text. Pathfinder 1e notes describe a GM-approved adaptation only; the modern panels show published but mechanically different Alarm rules.
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