Grenadier

Rogues who delve too deeply into Alchemical arts discover an explosive secret; Gunpowder. These rogues craft various instruments of destruction, and would rather answer a tense situation with a detonation.

Alchemical Knowledge

When you choose this archetype at 3rd level, you gain proficiency with Alchemist Supplies. In addition, your skill with this tool allows you to replicate certain magical phenomena. As an action you can create one of the following effects using your Alchemist Supplies:

You reproduce the Prestidigitation cantrip, choosing one of its listed effects.

You reproduce the Control Flames cantrip, choosing one of its listed effects, but at a range of 5 feet instead of 60.

You reproduce the Produce Flame cantrip.

Each of these effects are considered magical, and all attack rolls are made using your Intelligence as the Spellcasting Ability.

Explosive Savant

Starting at 3rd level you learn how to craft Gunpowder, Bombs, and Dynamite. The cost of components and time associated with crafting these items are listed below, as is the required Alchemist check in order to successfully craft the explosive. A failed Alchemy Check does not destroy the components but does take the same amount of time as a fully crafted explosive.

Item, Alchemy Check, Time

Gunpowder

DC 12, 20 minutes

Bomb

DC 15, 10 gp, 1 hours.

Dynamite

DC 15, 10 gp, 1 hour

If a creature is surprised or fails their saving throw by 5 or more, they take additional damage equal to your Sneak Attack. The Saving Throw DC for your explosives is calculated as follows:

Save DC=8+ your proficiency bonus + your Intelligence modifier

Improved Alchemy

At 9th level your knowledge of chemical concoctions Deepens. The damage from your explosives now counts as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.

Explosive Expert

By 13th level your practice crafting Explosive Devices has taught you new ways of increasing their effectiveness. You gain the following benefits:

You have resistance to damage dealt by your own explosives, and advantage on saving throws to resist their effects.

You can increase the length of fuse on your explosives, stalling their effects for up to 10 minutes after they've been lit.

Your explosives can now deal an extra 2 dice of damage. 

Mastery Of Destruction

When you reach 17th level, prolonged exposure to your chemical concoctions has permanently altered your form, and the destructive items you craft. You gain immunity to Fire damage, and your explosives deal double damage to structures and items not being worn or carried. Additionally, when an explosive you've thrown deals damage you can also add your sneak attack damage to the roll, provided you have not yet used your sneak attack this turn.