Variant Rules (Dragon Ball Supplement)
From D&D Wiki
The following are writeups and links to various variant rules this campaign should use.
When a creature is targeted by a spell, technique, or similar harmful effect that deals damage, they may use their reaction to initiate an attack clash. They make the same type of attack against them(melee weapon, ranged spell, so on), so long as they are within range of this attack, and instead of rolling to hit, both contestants immediately roll damage. Whoever rolled higher takes damage equal to the amount they rolled minus the failing roll. If they both deal the same damage, nobody takes any damage. If they were charging something, they may instead use this technique for the purposes of their attack so long as it is ready to be used. They use it as normal if they were to succeed so long as the triggering creature is within the area or directly targeted by it. Additionally, if it requires a saving throw, they automatically fail.
For example, creature A makes an unarmed attack against creature B, and B initiates an Attack Clash. B also makes an unarmed strike. A deals 9 damage, and B deals 28, thus, B wins the clash, dealing 19 damage to A. Additionally, B turns it into a Massive Hit, and knocks them back 15 feet.
Another example. Creature A is currently charging a Spirit Bomb, and Creature B makes a ki blast attack against them, turning it into a Death Beam. A uses their reaction to initiate a Attack Clash, and instead of making a ki blast attack, they use their currently charging Spirit Bomb. A deals 70 damage, and B deals 30, causing A to win. They must now use their Spirit Bomb, with B being in the radius.
When firing a beam at something, instead of dealing damage, you can instead propel yourself. When doing so, they move a number of feet in any direction equal to (the beam’s length × its width) ÷ 10, rounded down to the nearest 5. When attempting to land or grab onto an object, even if it would not incur falling damage, they must succeed a DC 12 Dexterity or Wisdom saving throw. On a failure, they fall prone or fail to grab the object.
One Currency System
While ki acts in a vacuum mechanically in 5e, in canon it is something of a universal lifeforce. This variant rule is intended to bring that concept into reality. Reiki points are equal to ki points. Spell slots are equal to a number of ki equal to 6 times their level. Chakra is worth half as many ki points, and psi points and aura points are worth a quarter as many ki points.