Let’s Create A Custom Spell
The rules can only take you so far when playing Dungeons and Dragons, even with the plethora of spells and casting options available. So, you may be tempted to craft your own custom spell for your character or campaign. But how can you do that while still maintaining some kind of balance and theme? Today, I will break down my process for making, testing and implementing custom spells into my games.
Choose Your Theme And Effect
Before you can start truly expanding your spell list, you need to find out what kind of problem your new magic will fix. Fireballs fix the problem of living enemies, and cure wounds fixes the issue with dead or dying party members. Second, you must choose a theme or damage type. For our example today, we will solve the problem of half-casters like paladins having low movement and a small area of effect damage. For the theme, I'd like to take on board some ideas from anime and use the woefully underutilized element of lightning in Dungeons and Dragons.
Find Familiar Spells
The designers of Dungeons and Dragons did a lot of work to try and cover all the scenarios they could. Therefore, there are bound to be spells that can work similarly to what you want. In our example, we will take a look at Misty Step and Lightning Bolt for inspiration. Misty Step allows for a character to teleport 30ft as a bonus action with a second-level spell. Lightning Bolt fires off a 100ft long and 5ft wide line of lightning dealing 8d6 damage to anything in its path and requires a dexterity saving throw with the price of a third-level spell slot.
Craft Your Spell Effects And Try To Balance It
So, how do we combine our Lightning Bolt and Misty Step to create something unique? First, we will take the range of Misty Step, making it 30ft, and then add the effect of Lightning Bolt on top. However, simply combining the impact of two spells can lead to unbalancing the game. If we were to have a lightning teleport, it would need to be something akin to a sixth-level spell, which our target demographic of Paladin wouldn't be able to cast.
To balance our new spell, we need to nerf down the Lightning Bolt effect while raising the cost above the second-level spell-slot used to cast it. There are several ways to do this, but for the simplicity of today's spell, we will cut down the lightning damage to 1/3 just as we reduce the 100ft range to 30ft, the same as Misty Step. With that, we can propose using a fourth-level spell slot and a bonus action to teleport 30ft, leaving behind a trail of lightning that demands a dexterity saving throw from anything in its path and dealing 3d6 points of lightning damage on a failed save and a half as much on a successful save. Other options can be to raise the damage slightly, to four or five d6s, but make creatures who succeed take no damage. Furthermore, we could make this spell a third level but balance it out by taking an action rather than a bonus action.
Add Some Flavor
All spells have components, whether material, somatic, or verbal, which opens up a lot of space to add flavor. Fireball, for example, requires sulfur bat guano and its somatics to point to a location in range. For our spell, we will require a metal rod or weapon of some kind to act as a lightning rod and verbal components of screaming to mimic the sound of thunder.
Playtest Your Spell
There is only one way to know if a spell will work and be over or underpowered. That is to test it out in the game. If you notice a custom spell is never used, it may need a buff to its power; conversely, if you or your players use it at every opportunity and avoid all the others, it may be a bit too powerful and need to be tweaked. For this example, this is a spell I have changed several times over its lifetime, and it has been used several times in games I have run until it reached its ultimate form, which is given below.
Iron Smite
4th Level Evocation
Casting Time: 1 bonus action
Range: Self (30-foot line)
Target: Self (30-foot line)
Components: V S M (A metal rod or weapon)
Duration: Instantaneous
Classes: Paladin, Warlock
You briefly transform into a roaring dragon made of lightning, blasting forward in a line and rending anything in your path apart, teleporting to an unoccupied space within range. Each creature between your point of origin and new location must make a Dexterity saving throw, taking 3d6 lightning damage on a failed save and half as much on a successful one. The lightning ignites flammable objects in the area that aren't being worn or carried.
At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the range increases by 5 ft, and the damage increases by 1d6 for each slot level above 4th.
