4th-level Spell: Inexorable Cannon

Dream Magic (Conjuration)

You connect yourself to an ancient relic from a bygone age, relaying coordinates to it as it begins charging up with arcane energy. At the start of your next turn, the cannon fires, opening a portal at a point within range and blasting an energy beam through it in a direction of your choice. All creatures in a line 120-feet long and 5-feet wide must make a Dexterity saving throw. A target takes 7d10 bludgeoning damage on a failure or half as much on a success.

If your concentration ends early, the cannon fires immediately, dealing 4d10 bludgeoning damage, or half as much on a successful save.

This spell does full damage against fortified structures and ships, and double damage against smaller objects.

• At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d10 per slot level above 4th.

Source: SMS (Tieleman's Cannon, modified)

• Casting Time: 1 action
• Range: 30 feet
• Components: V, S, M (a small lead ball and a pinch of gunpowder, both sourced from the Scattered Isles)
• Duration: Concentration, up to 1 round
• Ritual: No