While some artificers prefer to experiment within the confines of magically enhanced engineering or the crafting of magical items, others use raw magic and materials out of this world for their craft. Such is the case with Astral Architects, individuals that wield solidified starlight, or in simpler terms, hard light, to create walls and structures in mere seconds.

Astral Architects aren’t extremely common, usually found within the confines of the Astral Sea, or as travellers returned from such a place, as the secret to their craft is usually reserved to those that dare to wander outside the material plane.

While those belonging to this specialization do tend to prefer a simpler life of actual architecture once they learn how to harness hard light, others become full time swashbuckling explorers that wield their talents in impressive feats of improvisation, harnessing starlight to harm their foes with light, at the same time build fortresses to keep their allies safe and spend the night before moving on with their journey.

Astral Architect Spells

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

Artificer Level	Spells
3rd	Faerie Fire, Floating Disk
5th	Maximilian’s Earthen Grasp, Mirror Image
9th	Major Image, Tiny Hut
13th	Resilient Sphere, Secret Chest
17th	Arcane Hand, Wall of Force

Astral Fire

Beginning when you choose this specialization at 3rd level, you have learnt to wield the power of stars. You learn the Sacred Flame cantrip if you don’t know it already, it counts as an artificer spell for you, and it doesn’t count against your number of spells known. 

In addition, whenever you cast the cantrip, you may choose for the radiant flame to stay in your hand for up to 10 minutes. When you do so, it remains there for the duration, it harms neither you nor your equipment, and it sheds bright light in a 20-foot radius and dim light for an additional 20 feet.

Starlight Architecture

Also at 3rd level, you can wield hard light to create constructs of starlight. You have a number of uses of this feature equal to your proficiency bonus, regaining all expended uses when you finish a long rest, and one expended use when you finish a short rest. You can use this feature to cause either of the following effects:

• Wall of Starlight. As an action, you can cause a wall of light to rise from a solid surface you can see. This wall is 5 feet tall, 10 feet wide and 2 feet deep, made out of a shimmering crystalline material whose appearance resembles the night sky. It emits dim light for 5 feet around it and it is opaque. You can make the wall smaller, if you do so desire, but it must still be shaped like a wall. The surface upon which it is created must be an unoccupied space, the wall’s extension at the moment it is created must be an unoccupied space, and the surface must be large enough to fully hold at least one of the sides of the wall. The construct counts as a resilient Medium object made of Mithral for the purposes of its HP and AC, and it lasts for 10 minutes after it’s been created.
• Starlight Warp. You can use your action to cast the Passwall spell without expending a spell slot. When you cast the spell this way, the opening  emits dim light for 5 feet around it, and it is made out of a shimmering crystalline material whose appearance resembles the night sky.
• Shift of Starlight. As an action, you can shift the floor around you into a shaky, crumbling material of light. Creatures other than you within 30 feet of you, or in a 15 foot cone originating from you, must succeed on a Dexterity saving throw against your spell save DC or be knocked prone. The floor’s material becomes, instead, a shimmering crystalline material whose appearance resembles the night sky, and it emits dim light for 5 feet around it. The floor becomes difficult terrain for all creatures other than you, and whenever a creature moves through it, glass shattering-like sounds occur, giving any creature disadvantage on Dexterity (Stealth) checks when moving through it. The shift in the floor’s material lasts for 10 minutes.
• Starlight Nebula. As a bonus action, you can create a 10-foot radius sphere of astral smoke centred on a point you can see, made of astral, luminescent fog. It emits dim light for 5 feet around it , and it is heavily obscured inside it. The sphere lasts for 1 minute or until you dismiss it (no action required).

Improved Astral Fire

Starting at 5th level, whenever you deal damage to a creature with a spell, you add 1d8 radiant damage to the spell’s damage.

Astral Constructs

At 9th level, your proficiency with your Starlight Architecture improves even further. Whenever you use your Shift of Starlight, Starlight Warp, Wall of Starlight or Starlight Nebula features, you may choose for them to last until they are destroyed or dispelled, rather than for its normal duration. 

In addition, you can improve your Starlight Architecture by infusing it with magic, expending a spell slot to enhance their functionality. You can use this feature without expending a spell slot once, counting as a 1st level spell slot, regaining the ability to do so again when you finish a long rest.

• Improved Wall of Starlight. Whenever you use your Wall of Starlight feature, you may expend a spell slot (no action required) to enhance its dimensions. You can enhance the wall’s dimensions (its height, width and depth, each of them) by a combined number of feet equal to 15 feet per level of the slot. If you expend a spell slot of 1st or 2nd level, the wall becomes Large, if you expend a spell slot of 3rd or 4th level, it becomes Huge, and if you expend a spell slot of 5th level, it becomes Gargantuan.
• Improved Shift of Starlight. Whenever you use your Shift of Starlight feature, you may expend a spell slot (no action required) to enhance its dimensions. You can enhance the radius by 5 feet per level of the slot, or the cone’s extension by 10 feet per level of the spell.
• Improved Starlight Nebula. Whenever you use your Nebula, you may expend a spell slot to enhance its dimensions. The sphere’s radius increases by 5 feet per level of the slot.

Celestial Recall

By the time you’ve reached 15th level, as a bonus action, you may recall a piece of your Starlight Architecture when the time is right. Hostile creatures within 10 feet of it must succeed on a Constitution saving throw against your spell save DC or take 9d4 radiant damage, taking half as much on a successful save.

For every two times you use your Celestial Recall feature, if you have an expended use of your Starlight Architecture feature both times you’ve activated your recall, you regain a use of your Starlight Architecture feature. To simplify the explanation, if you have expended a use of your Starlight Architecture feature when you use this feature, you regain “half” a use. This has no impact on the amount of times you can use this feature, unless you use your Celestial Recall again, regaining another half, and with that, a full use your Starlight Architecture feature.