Breaching Charge

You hold the materials used in the casting of this spell for the length of the casting time. During this time, you also choose a command word by speaking it to the charge while casting the spell. After the end of the round, the charge glows dimly with an orange light. Whenever you press this charge up to a surface, it will stick to the surface. The next time you speak the command word chosen within the charge’s range of hearing, 60 ft., the charge will explode in a blast of fire. Any creature within 15 ft. of the blast must succeed on a Dexterity saving throw, or take 7d6 fire damage and be forced back 10 feet. Any inanimate, non-magical charges within the 15 ft. radius of the blast will automatically fail this saving throw and take maximum damage from the spell. The blast deals double damage to any surface made of wood, stone, or a form of cement, and ignores any resistances of that surface. Any creature behind a wall destroyed by this spell must make the Dexterity saving throw or take damage equal to the damage rolled for the wall – the wall’s hit points on a failure, or half damage on a successful save. 

During the casting of the spell, you can also speak the name of another creature that you know as long as your command word. That creature can now speak the command word to detonate the charge. You or another creature whose name was spoken in the casting of the spell can expend a spell slot of 1st level or higher to change the creature or the command word of the charge. Only one creature and command word can be assigned to the charge. A creature can only be assigned to one charge at a time. The assigned command word can be “None” or “Idle”, which will cause the charge to not detonate until it is assigned a word. If this spell is cast using a scroll, the command word is written on the scroll, but the user can be anyone of the caster’s choice. If the Identify spell is cast on the charge, it will reveal who can detonate the charge and what the command word is. A Dispel Magic spell cast while the box is within range will remove the magical properties from the box, but an Anti-magic field or similar effect will only render the charge inert while within the range and prevent the explosion from reaching within the area of the effect.