Beam Battles in D&D
Who doesn't love the idea of holding off an unrelenting force while meeting it with one of your own. Your friends won't just sit on the sideline waiting for your to die, however. They'll be able to assist you or hinder your opponent.
War Beam
1st-level Evocation
- Casting Time: 1 action or 1 reaction
- Range: 200 feet
- Components: V, S
- Duration: Until the spell deals damage or kills a creature
You choose one creature within range to make a dexterity saving throw as a beam of arcane light shoots from you. Creatures who fail take 4d6 force damage on a failed save, or half as much on a successful one. A creature who is able to cast this spell can choose to cast this spell as their reaction, rather than make the saving throw. If the target casts the spell as well, a Beam Battle begins.
At Higher Levels When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 3d6 for each slot level above the 1st. If you cast this spell as a 9th level spell and win a beam battle, the spell will kill the target instead.
Beam Battle
Once two creatures have casted the spell War Beam at each other, a beam battle will begin. Starting from the two creatures and meeting in the middle, an arcane bolt will connect the two, causing a spark to manifest in the middle, equal distance from both casters and taking up a 5 foot radius sphere.
Touching the Beams
Touching this beam for the first time or ending their turn standing in the beam will cause a creature to take 1d6 force damage. Touching the spark for the first time or ending their turn standing in the spark at the center of the beam will cause the creature to take 3d6 force damage. This damage ignores resistance and immunities to force damage.
Starting the Dual
When the beam battle begins the caster subtracts the level they casted the spell from the level their target casted it from. This will determine which stage the beam battle will begin with. (For example, if both cast at the 1st level, the battle will start at 0 points, but if the caster were to cast the spell at 5th level, the spell would begin at 4 points towards the target) Once the battle reaches 10 points towards one caster or the other, the battle is over, and the loser will receive force damage equal to the number of dice both casters would have rolled. This damage will ignore resistance and immunities to force damage.
Gaining and losing points
During the beam battle, both creatures are immune to all forms of damage, but can still be distracted, as well as being able to cast cantrips. Any cantrip the caster in the battle knows can now be casted as a bonus action during the beam battle. The caster can also use their action to push the beam towards their opponent by one point.
If a caster is struck by an attack, they must make a constitution saving throw (DC 10 or half the damage they would have taken, whichever is higher). If they fail, the beam moves one point closer to them. This can only occur once per round, regardless of the source of damage.
If the caster chooses to cast a spell of 1st level or higher, the beam moves one point closer to them per level of the spell they are casting.
Other creatures can use their action to assist one caster in the duel. They cannot take any other action when they do this, but can make an arcana check against the opposing caster's spell save DC. If they succeed, the beam will move one point closer to the opposing caster.