In this installment of Arcane Adventures,we look as four spells that target a fortification like a castle or keep.

Bickering Whispers

5th-level enchantment (bard, warlock, sorcerer wizard)
Casting Time: 10 minutes
Range: Touch
Components: V, S, M (a rose dipped in blood that is burned during the casting)
Duration: 1 day

You enchant a fortification such that those humanoids within find it difficult to work together. All creatures within the fortification must succeed on a Wisdom saving throw. Distrust grows and tempers become short as the enchantment poisons the minds of anyone that fails the saving throw. Creatures that fail have their attitudes toward all other humanoids within the castle shift to hostile. Attitudes toward anyone whom the target possesses a close bond with are unaffected. For those that fail the saving throw, Charisma checks to influence others are made with disadvantage.

Those within a magic circle are protected from the effects of this spell, and the effect ends if a creature leaves the fortification. Creatures who fail the saving throw that leave and return to the area are still affected when they return.  

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the duration increases by 1 day for each slot level above 5th.

Castle of Secrets

7th-level conjuration (bard, cleric, wizard)
Casting Time: 1 hour
Range: Touch
Components: V, S, M (a platinum and diamond key worth 10,000 gp)
Duration: 1 year

Within a fortification such as a keep or castle, you conjure an extradimensional 20-foot-square secret room with two secret passages connecting different existing locations within the structure. The passage entrances are hidden behind secret doors, DC 20 Wisdom (Perception) to locate. The room exists as a demiplane that appears to be constructed of the same material as the fortification.

You do not control the placement of the secret entrances. They appear randomly inside the structure, and even you do not know where they are. When you cast this spell, the material component disappears and reappears inside the secret room. Anyone holding the focus key within the secret room knows the location of all the secret passages and rooms within the structure, even those not created by this spell. In addition, while standing in the secret room, the key can be used to lock the secret doors to the room (DC 20). If the focus key is removed from the secret room, the spell ends prematurely. When the spell ends, the doors disappear, and any creatures or objects inside the demiplane remains trapped there.

Each time this spell is cast on the same structure before the duration ends, the locations of the secret doors move to new, random locations.

Decay Fortifications

5th-level transmutation (druid, ranger, warlock, wizard)
Casting Time: 1 minute
Range: 30 feet
Components: V, S, M (a pouch of sand)
Duration: 1 day

You target a fortified structure that you can see, willing it to ruin. Moss and lichen spread across stone, causing it to flake, wood begins to rot, portcullises rust, and vines spread across its walls. Break DCs for doors, walls, and windows decrease by 2, and the damage threshold for each decreases by 5. In addition, you may designate one wall to become covered in ivy, giving advantage to Strength (Athletics) checks made to climb that wall.

When this spell ends, the fortification regains its former strength, and the ivy crumbles to dust.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the duration increases by 1 day for each slot level above 5th.

Harden Defenses

5th-level transmutation (bard, cleric, paladin, wizard)
Casting Time: 1 minute
Range: 30 feet
Components: V, S, M (a brick)
Duration: 1 day

You target a fortified structure that you can see, and you reinforce it. Walls become more solid, doors reinforce with iron bands, and even windows thicken. Break DCs for doors, walls, and windows increase by 2, and the damage thresholds increase by 5, even if they did not previous have one. The DC to open locks within the structure increases by 2.

When this spell ends, the fortification reverts to its former strength.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the duration increases by 1 day for each slot level above 5th.

Adventure Ideas

While these spells have obvious implications during a battle that takes place in or around a fortified stronghold, there are more options to add excitement to your campaign:

• Siege.These spells can easily be used to add flavor to war stories. Harden defenses might be used by a party trying to resist a siege, while decay fortifications is perfect should they be laying siege to an enemy. Bickering whispers might also be used to disrupt a fortification’s organized defense, especially if the fortification contains multiple factions. However, bickering whispers is not effective against those who have a close bond, and thus won’t help against a family or tightly connected order of knights.
• Hidden Secrets. Castle of secrets is perfect for a party that wants to hide something inside their own fortification or have a safe location to rest while exploring a ruin… if they can find it. The same spell is also useful for locating other secret locations if the party feels like they have overlooked something within their new keep. Castle of secrets does have a weakness. The key focus controls access to the secret doors and can be removed to end the spell and potentially trap the characters, or their enemies, in the demiplane! If used to trap an enemy, that enemy might be unexpectantly released should someone cast the spell again.
• Negotiations. Bickering whispers is perfect for social encounters the characters want to disrupt. Whether trying to prevent a treaty from being signed or breaking up a wedding, this spell is perfect to sow discord.
• Break In. Decay fortifications is useful for a siege, no doubt, but don’t underestimate the value of a wall of ivy that the residents don’t know about when trying to climb a wall and sneak inside a fortification for a quick heist.

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