How to Play Sai, Master Thopterist: Keen Engineering Deck Guide

Keen Engineering is the mono-blue artifact deck in the Foundations Commander lineup, and its commander Sai, Master Thopterist is one of the best engines you can find at three mana. This guide walks through how to pilot the deck: what to keep, what to play first and how to turn a pile of Thopters into a win.

The engine

Sai, Master Thopterist does two things:

• Whenever you cast an artifact spell, you create a 1/1 flying Thopter.
• For {1}{U}, you can sacrifice two artifacts to draw a card.

Thopters are artifacts, so Sai feeds himself. Cheap artifacts become two bodies, and spare bodies become cards. The deck’s job is to cast as many artifacts as possible, then cash them in for value or turn them sideways for damage.

Mulligan and opening hand

You want two to four lands and at least one cheap artifact or mana rock. Good keeps include cards like Sol Ring, Mind Stone, Arcane Signet, Silver Myr or Palladium Myr. Hands with only expensive artifacts like Myr Battlesphere or Darksteel Juggernaut are slow; ship them unless the mana is excellent.

Turns 1 to 4: build the board

Play Sai on turn three whenever you can. Before that, deploy mana rocks and Myr. From then on, sequence your turns so Sai is on the battlefield before you cast artifacts, otherwise you miss the Thopters.

Cards that make this phase strong:

• Etherium Sculptor and Foundry Inspector make your artifacts cheaper, so you cast more of them per turn.
• Thoughtcast costs almost nothing with a few artifacts out and refills your hand.
• Thopter Fabricator makes a Thopter whenever you draw your second card in a turn, which Sai’s sacrifice ability makes easy.
• Whirler Rogue brings two more Thopters and can make one of your creatures unblockable.

The mid-game: card draw versus pressure

The real skill with Sai is deciding when to sacrifice. Drawing a card for two Thopters feels great, but each Thopter is also a point of flying damage. A good rule of thumb:

• Sacrifice when you’re short on cards, when a board wipe is likely, or in response to removal on your artifacts.
• Keep your Thopters when you have an anthem coming, like Master of Etherium or Chief of the Foundry, or when you’re close to lethal.

Thopter Spy Network and Tamiyo’s Logbook keep the cards flowing without spending your board. Padeem, Consul of Innovation gives your artifacts hexproof and draws you a card each upkeep when you control the artifact with the highest mana value.

Protection and interaction

Blue gets the best tricks in the deck. Hold up Counterspell or Negate for board wipes aimed at your army. Propaganda keeps aggressive decks off your back while you build. Aetherize bounces every attacking creature, a one-sided fog against big swings, and Nevinyrral’s Disk is your reset button if an opponent pulls far ahead (your Thopters die too, so time it well).

How the deck wins

There are three main routes:

• Flying army. Ten or more Thopters plus Master of Etherium or Chief of the Foundry ends games quickly.
• Big robots. Myr Battlesphere, Steel Hellkite and Darksteel Juggernaut are threats your opponents must answer.
• Grinding. With Psychosis Crawler on the battlefield, every card Sai draws makes each opponent lose a life.

Five easy upgrades

If you want to take the deck a step further, these are great first additions:

• Ornithopter and Memnite: zero-mana artifacts mean free Thopters.
• Emry, Lurker of the Loch: cheap with a few artifacts out, and it lets you recast cheap artifacts from your graveyard for even more Thopters.
• Retrofitter Foundry: a mana sink that turns spare mana into more tokens.
• Cranial Plating: turns a single evasive Thopter into a lethal threat.
• Tezzeret’s Gambit: draws two and proliferates, and you can pay life instead of blue mana.

Keen Engineering rewards careful sequencing more than most precons. Learn when to swing and when to sacrifice, and Sai will carry you through a lot of games.