What follows are some ideas for arcane spells. Some of these could be divine spells as well.
1. “Spell Mime” – This spell creates an illusionary humanoid figure. That figure mimes the somatic gestures, as well as the movements required to handle material components, for the last spell that was cast in the area of the Spell Mime’s effect. The figure continues to mime in this manner until the duration of the Spell Mime ends. While this spell is in effect, it grants advantage to any arcane or divine caster that attempts to identify the spell the being mimed. This spell does not produce sounds related to verbal components. The figure is faceless.
2. “Spell Scribe” – This spell creates a temporary illusionary arcane script that shows the formula for casting the last spell that was cast in the area of the Spell Scribe. The script appears on any flat surface the caster designates, but this surface cannot be smaller than an area proscribed by the width and length of the caster’s hand, nor can the surface area be longer or wider than the caster’s height. If the last spell cast was memorized from a spellbook then the script created by the Spell Scribe duplicates the arcane writings of the spellcaster that cast that spell. If the last spell cast was not memorized from a spellbook then the script appears in the form and style of the caster’s own arcane writing style.
3. “Spell Chime” – This spell temporarily links the caster to an object that can be manipulated to produce sound (a lute or a warhorn, for example, or something like a large church bell). For the duration of this spell, any time the caster successfully casts a spell, the object linked to the caster sounds off. This spell automatically fails if the caster is attuned to three magic items. It’s duration automatically ends if the caster becomes attuned to three magic items.
4. “Spell Echo” – This spell recreates any and all sounds produced by the last spell to have been cast in the area of the Spell Echo’s effect prior to the Spell Echo being cast. Secondary sounds are not produced. A secondary sound would be any sound produced as a result of the spell, such as a grunt of pain from being slashed by a Blade Barrier, or the sound of a statue toppling over after it was struck by a Bigby’s Hand spell. Note: The sounds of the blades slashing a creature, as well as the sound of the conjured hand striking the statue, would be produced by the Spell Echo. This spell lasts as long as the spell whose sounds the Spell Echo is recreating.
5. “Spell Informant” – Once cast, this spell lingers in an area designated by the caster. Any time a spell is cast in that area, the Spell Informant sends a magical message that appears in the mind of the spellcaster. This message gives the name of the being that just the spell. Upon delivery of this message the Spell Informant ends. A caster may not have more Spell Informants active than his or her highest spellcasting level. If the being that is being identified is known by multiple names, the Spell Informant uses the last name the being was called by.
6. “Blood Coins” – After you cast this spell, you may select a number of coins no greater than five times your caster level. If any of the coins you select have been touched by someone other than you who has either committed a murder or assisted in the commission of a murder within the last 24 hours, then those coins will begin to ooze blood. The coins bleed for a number of rounds equal to your caster level, or until you spend a bonus action to end the spell.
7. “Forge Echo” – This spell may be cast on any object that was made by an ironsmith. The spell reproduces the sound of the smith’s hammer as it was being used to forge the object the spell was cast upon. If multiple smiths worked an object at the same time, all their hammers sound off.
8. “Similarity” – This spell causes an item of clothing worn by a creature within the spell’s range to appear identical to another item of clothing of the same kind worn by a different creature within the spell’s range. For example, the dust and mud covered boots of a passing mercenary may be made to temporarily resemble the clean, ornate boots of a nobleman riding in the other direction. At higher levels, the caster may select multiple of the same kind of clothing item to appear identical. For example, the travel robes of a party of adventurers may be temporarily made to resemble the robes of one of the king’s guards manning the castle gate that the PCs wish to get past. This spell ends after one hour, or when any of the clothing items involved in the spell become separated by a distance longer than the range of the spell.
9. “Coin Curse” – The caster may select one object no larger than a sack or a small chest when this spell is cast. If any coins within the object are removed by any creature other than the caster, the coins deliver an electric shock to the creature. This causes 1 HP of damage. At higher levels, this spell may be cast on larger objects. If cast as a 9th level spell, this spell may target the dwelling of the caster (such as a tower, castle, dungeon abode, or the lair of a dragon).
10. “Forge Sacrifice” – This spell requires at least one metallic object produced from metal smelted in a forge. If the object is placed within a cold or otherwise inert forge, that forge becomes instantly hot enough to melt ore and extract metal. This effect lasts for one hour per object sacrificed. Only 24 objects may be sacrificed in this manner per casting.