All rune shots are magical effects. If a rune shot requires a saving throw, its DC is the same as your spell save DC.
Accuracy. You guide your rune shot to strike with unerring accuracy. When you use this rune shot, you have advantage on the attack roll.
Black Penny. You empower your rune shot to strike down a nearby foe. When you use this rune shot, you do not have disadvantage on attack rolls made against targets within 5 feet of you.
Brutal. You empower your rune shot to strike with greater force and savagery. When you use this rune shot and hit a creature with an attack, the target takes an extra 2d6 damage, and the attack scores a critical hit on a roll of 19 or 20.
Detonator. You imbue your bullet with explosive energy that detonates after your attack. When you use this rune shot and hit a creature with an attack, that creature and all other creatures within 10 feet of it take an extra 2d6 force damage each.
Earth Shaker. Your rune shot carries an enchantment that makes the ground tremble. When you use this rune shot and hit a creature with an attack, that creature and all other creatures within 20 feet of it must succeed on a Strength saving throw or be knocked prone.
Electro Leap. You empower your rune bullet with electricity, causing tongues of lightning to spring from your target to strike another target nearby. When you use this rune shot and hit a creature with an attack, that creature and one other creature of your choice within 15 feet of it take an extra 2d6 lightning damage each.
Fire Beacon. Your rune shot is empowered to strip away mundane and magical concealment from your targets. When you use this rune shot and hit a creature with an attack, any attack roll against the creature has advantage if the attacker can see it, and the creature cannot benefit from cover. This effect lasts until the start of your next turn.
Freeze Fire. Your rune bullet carries the bite of winter. When you use this rune shot and hit a creature with an attack, that creature takes an extra 2d6 cold damage and must succeed on a Constitution saving throw or have its speed reduced by 10 feet until the start of your next turn.
Heart Stopper. The deathly arcane power of this runeetched bullet is intended to bring a swift end to your target. When you use this rune shot and hit a creature with an attack, that creature takes an extra 2d6 necrotic damage and must make a Constitution saving throw. On a failed save, the creature cannot regain hit points until the start of your next turn. This rune shot has no effect on constructs or the undead.
Iron Rot. You imbue your rune shot with the power to corrode metal. When you use this rune shot and hit a steamjack or a creature wearing nonmagical metal armor, the target takes a permanent and cumulative −1 penalty to its AC. Armor reduced to an AC of 10 is destroyed. Repairing this damage requires a successful DC 15 Intelligence check and 1 hour of work with tinker’s tools. In addition, any nonmagical item that is hit by this rune shot, weighs up to 20 pounds, and isn’t being worn or carried immediately corrodes and is destroyed.
Molten Shot. Your rune shot becomes white-hot as you infuse it with fiery magical energy. When you use this rune shot and hit a creature with an attack, that creature takes an extra 2d6 fire damage and 1d6 fire damage at the start of your next turn. Any flammable object hit by this shot ignites.
Phantom Seeker. A bullet inscribed with this rune shot becomes ethereal, curving in flight to seek out your target. When you use this rune shot and make an attack, do not make an attack roll for the attack. Instead, choose a target within the normal range of your weapon. That creature must make a Dexterity saving throw. On a failed save, the creature takes damage as if it were hit by the bullet, plus an extra 1d6 force damage. On a successful save, the creature takes half as much damage. You do not need to be able to see your target to use this rune shot.
Silencer. You completely muffle the sound of your shot, and your firearm produces no sound when it discharges. When you use this rune shot and hit a creature with an attack, that creature cannot shout or speak until the start of your next turn.
Thunderbolt. Your rune shot hits with thunderous impact. When you use this rune shot and hit a creature with an attack, that creature takes an extra 2d6 thunder damage and must succeed on a Strength saving throw or be pushed 20 feet away from you.
Trick Shot. You empower your bullet to ricochet from your initial target and strike another. When you use this rune shot and make an attack, after the attack, choose a creature within 30 feet of the original target and then make an attack roll to hit the chosen creature. If the attack hits, the chosen creature takes damage from the attack as normal, and any special effects of the attack apply to the creature as normal.