Sapper

An artificer who specializes as a Sapper uses their knowledge of materials and magic to alter the battlefield. They build and destroy fortifications, change the landscape, and operate siege weapons with maximum effectiveness, all to bring favorable conditions to their allies and ruin what defenses their foes might construct for themselves.

Level 3: Tool Proficiency

When you choose this specialization at 3rd level, you gain proficiency with carpenters' tools and masons' tools, assuming you don’t already have it. You also gain a set of carpenter's tools or mason's tools for free. 

Level 3: Weapon Proficiency

At 3rd level, you gain proficiency with mauls, war picks, and heavy crossbows. You can add your proficiency bonus to your attack rolls when using carpenters' tools, masons' tools, digging equipment (such as mattocks and shovels), or portable rams as improvised melee weapons. 

Sapper Spells

You always have certain spells prepared after you reach particular levels in this class, as shown in the Sapper Spells table. These spells count as artificer spells for you, but they don't count against the number of artificer spells you can prepare. 

Artificer Level	Spell
3rd	grease, unseen servant
5th	pass without trace,  spike growth
9th	daylight, plant growth
13th	hallucinatory terrain, wall of fire
17th	passwall, wall of stone

Level 3: Siege Striker

At 3rd level, you are trained in finding the weaknesses of buildings and other objects made from nonliving materials. You deal double damage to objects and structures when making weapon attacks.

You also have advantage when making ability checks to find and identify weak points or stress-bearing points in structures, as well as when figuring out which direction a structure might fall when it is weakened or destroyed.

Level 3: Sapper's Charge

Also at 3rd level, you learn to create a small magical charge that explodes after a preset delay. Over the duration of a short or long rest, you can use your tinkerer's tools or carpenter's tools to create 2 explosive charges, each weighing 1 pound. The number of charges you can carry is equal to your proficiency bonus.  

As a bonus action, you can activate the charge, setting it to detonate after a delay of your choice ranging from 12 seconds to 60 minutes. Once activated, the charge cannot be deactivated, but can be destroyed without exploding. It has an AC of 10 and 5 hit points. You can touch an active charge as an action to destroy it or cause it to immediately detonate. When the preset time expires, the charge detonates. Each creature or object within a 5-foot radius must make a Dexterity saving throw equal to your spell save DC and take 2d6 fire damage, or half as much on a successful save.

The explosion ignites flammable objects in the area that aren't being worn or carried. The sound of the explosion is audible out to 200 feet from the device's location.

You can incorporate a flask of alchemist's fire in the construction of your charge. If you do so, the radius of the fiery explosion increases to 15 feet. 

Level 5: Demolitioner's Gel

At 5rd level, you learn to conjure a ball of unstable gel that is charged with destructive energy. As an action, you can conjure a 3-inch diameter sphere of this sticky gel in an open hand, and as part of the same action, you can adhere it to any surface within 5 feet of you. The sphere has an AC of 13 and 1 hit point. It is soft and pliable, but can't be divided.

It is immune to all types of damage, except acid, fire, lightning, and thunder. When the gel takes fire, lightning, or thunder damage, it explodes. Each creature within a 20-foot radius of the gel must make a Dexterity saving throw equal to your spell save DC and take 6d6 thunder damage, or half as much damage on a successful save. Each nonliving object or structure within the area of the explosion takes double the amount of damage.

The booming sound of the explosion is audible out to 600 feet. If not triggered to explode, the gel vanishes harmlessly after 1 hour. Acid harmlessly dissolves the gel. You can conjure a sphere of this gel again after you finish a short or long rest.  

Level 5: Battlefield Sculptor

Beginning at 5th level, you can conjure a magical landscaping tool of your choice and use it to quickly move the earth around you. With 30 minutes of work with this tool, you can reshape dirt, sand, clay, and gravel in an area of terrain no larger than 50 feet in any manner you choose. You can raise or lower the area's elevation, create or fill in a trench, erect or flatten a wall, or form a pillar.

The extent of any such changes can't exceed half the area's largest dimension. So, if you work a 50-foot square, you can create a pillar up to 25 feet high, raise or lower the square's elevation by up to 25 feet, dig a trench up to 25 feet deep, and so on.

Because the terrain's transformation occurs slowly, creatures in the area can't usually be trapped or injured by your movement of the ground. The tool can't manipulate natural stone or stone construction. Large plants, trees, rocks, and structures shift to accommodate the moved terrain.

Only you can use the tool; anyone else's attempt to grasp it passes through the tool without effect.

The tool vanishes after 1 hour. If you used the tool to change the terrain, you gain one level of exhaustion when the 30 minutes end, which remains until you finish a short or long rest. You can use this ability twice, and you regain all expended uses when you finish a long rest.

Level 9: Homewrecker

Beginning at 9th level, whenever you use your action to attack with a maul, a warpick, a heavy crossbow, or an improvised weapon, you may strike twice. 

In addition, your attacks with weapons, siege weapons, and spells deal additional damage to objects, structures, or constructs equal to your Intelligence modifier.

Level 9: Siege Herald

At 9th level, you can aim and fire a siege weapon as a single action, and you add your proficiency bonus to the attack roll when you fire a siege weapon.

If you cast unseen servant while touching a siege weapon, the spell is altered. The magical servant can and will use an action at the end of each of your turns to continually load the siege weapon with any suitable ammunition that is within 15 feet of the weapon. The servant is bound to that siege weapon and can't be commanded to do any other task.

Level 15: Castlebane

Beginning at 15th level, you may, as an action, cast earthquake without expending a spell slot. You may cast it from the position of either one of your undetonated charges or explosive gels, causing them to explode instantly.

You can use this ability again after you finish a long rest.