Building a Commander deck with an AI assistant comes down to seven steps: pick a commander, give the assistant a plain-language brief, turn its draft into a real list, fill the gaps with a search that understands what cards do, take suggestions that are scored against your deck, validate legality, then do a budget pass. In Mana Grove that is Grover, our AI deck assistant, for the brief and the draft; Scry, our AI-powered card search, for the gaps; Tutor, our smart deck recommendations, for the scored picks; and the deck builder's Validation and Analysis tabs for the checks. The Free plan includes 20 Grover messages and 100 Scry searches a month, so you can run the whole method before paying for anything.
This guide walks through each step, with the exact prompts to type and the checks to run. One rule up front: Grover is a deck-building assistant, not a rules authority. It drafts, refines and answers questions as a starting point. You make the calls, and you verify rules against the Comprehensive Rules.
Try Grover: Grover, the AI deck assistant shows what it drafts from a short brief, with two dated examples.
Step 1: choose a commander, and know its colour identity
Everything in a Commander deck follows from the commander: the colours you can play, the plan, the budget. Pick a legendary creature with a plan you can describe in one sentence, because that sentence becomes your brief. A few with an obvious plan:
- Krenko, Mob Boss, {2}{R}{R}: taps to create a Goblin token for each Goblin you control. The plan is Goblins, and lots of them.
- Sythis, Harvest's Hand, {G}{W}: whenever you cast an enchantment spell, you gain 1 life and draw a card. The plan is enchantments.
- Giada, Font of Hope, {1}{W}: every other Angel enters with extra +1/+1 counters, and Giada taps for {W} to cast Angel spells. The plan is Angels.
- Isshin, Two Heavens as One, {R}{W}{B}: abilities that trigger when a creature attacks trigger an additional time. The plan is attack triggers.
Colour identity is the rule that trips up new builders. Every card in the 99 must fit inside the commander's colour identity (Comprehensive Rules 903.4 and 903.5c), which includes every mana symbol in the card's rules text, not only the ones in its cost. Alesha, Who Smiles at Death costs {2}{R}, but the {W/B} symbols in her ability give her a black, red and white identity. The deck builder asks for your commander when you create a Commander deck precisely because the legality checks depend on it. Browse candidates on the Commander hub.
Step 2: write a brief Grover can act on
Open Brew, then Build with AI. Grover has two modes: Build a deck, where it assembles a full draft from your prompt, and Chat with Grover, for questions. The quality of the draft tracks the quality of the brief. Four things belong in it:
| Part of the brief | Why it matters | Example wording |
|---|---|---|
| The format | "A Commander deck" and "a Modern deck" produce very different lists | "Build me a Commander deck" |
| A direction | A commander, a theme, a colour pair or a strategy | "a lifegain deck", "Goblins with Krenko", "mono-white" |
| Your constraints | Cards you insist on, cards you do not own, the table you play at | "for a casual pod", "Bracket 2", "no infinite combos" |
| The ask | What you want back: a full list, a package, a ranking, a cut | "give me the commander and the core of the list" |
Prompts in this shape work well as a first message:
- "Build me a lifegain Commander deck my casual pod won't hate. Bracket 2." Also choose "Target bracket: 2" in the deck builder, which sends the target with the build.
- "My mono-white Commander deck keeps losing to big creatures. Which white cards answer them and stay on theme?"
- "What are the best board wipes for a mono-white Commander deck? Rank your top five."
- "How does myriad work with Isshin, Two Heavens as One?"
Keep prices out of the prompt. Budget is a job for step 7, where the tools are better at it. If you are unsure which bracket to ask for, Commander brackets explained covers what Bracket 2 permits.
Step 3: turn the answer into a list
In Build a deck mode there is nothing to copy: Grover assembles the draft itself, you can watch the build progress, and the list lands in the deck builder for you to review. From there, ask for changes in short follow-ups: "lower the curve", "more removal", "cut the infinite combo". Every refinement shows you the proposed changes before they are applied, so nothing moves without your approval, and your recent builds stay on the same page so you can pick one back up later.
If you started in chat instead, create the deck yourself under Brew, then New Deck, pick Commander, name your commander, and add the cards Grover named by searching for them in the editor. Deck Builder Basics covers the editor's tabs.
Either way, once the list is in the deck builder you can keep talking to Grover about that specific deck from its Ask AI tab. That is where a prompt like "This is at 104 cards. What do I cut to get to 100 and why?" belongs, because the deck is attached to the conversation.
Step 4: fill the gaps with Scry
A first draft usually has holes: not enough removal, no way to recover from a board wipe, a missing win condition. This is where a search that understands meaning beats a search that needs the exact card name. Scry lets you describe the job a card should do, in your own words, from the card catalog or inside the deck editor:
- "board wipe that spares my own creatures"
- "return target creature card from my graveyard to the battlefield"
- "artifacts that make my dragons cheaper"
Results are ranked by how well each card's actual behaviour matches the description, so the more specific you are, the better the list. When a result misses, click Not relevant on it; the card leaves your results and your feedback improves future rankings. When the constraint is exact (a set, a colour identity, a mana value), reach for the filter sidebar instead, and combine the two: describe the effect first, then tighten with filters. Getting Better Search Results has more examples.
Step 5: take Tutor's synergy-scored picks
Once the deck holds at least 10 cards, the Suggestions tab starts proposing cards, and it refreshes on its own as the list changes. The picks come from Tutor, our smart deck recommendations, and they are computed for the deck you are building: Tutor reads your mana curve, your colour identity, the cards already in the deck, the cards in your collection, the format you chose and the way you play.
Every pick carries a synergy score, shown as a scored ring on the card in the Suggestions tab and as a percentage in the deck builder panel. The score is how strongly Tutor rated that card against this deck, and it is what the list is ranked by. Treat it as a ranking signal, not a verdict. Most picks also carry a short hint line naming the signal that put the card on the list, such as a card in your deck the pick pairs with or the spot on your curve it fills. Add puts a card straight into the deck; Dismiss hides a pick you do not want and is kept as feedback. Deck Recommendations Explained goes deeper.
Step 6: validate legality
Legality checks run as you build, against the format you picked, and the Validation tab holds the full report: deck size (exactly 100 cards including the commander, rule 903.5a), copy limits (one of each card that is not a basic land, rule 903.5b), the commander itself, and colour identity (rule 903.5c). A card outside your commander's identity is flagged as a colour identity violation, and a card that is not legal in Commander shows up as not legal in the format. Fix every flag before game night, not at the table.
Then open the Analysis tab and read the numbers: the mana curve, the colour distribution, the average mana value and the average number of lands in an opening hand. If the land count looks light, How Many Lands Go in a Commander Deck? has the table.
Step 7: the budget pass
Do the budget pass last, when the deck already works, so you know which cards are load-bearing. The Suggestions tab's filters include a budget filter that keeps Tutor's picks inside your price range, which makes it the fastest way to find a replacement for the one expensive card in each slot. Swap one card at a time, re-read the curve, and keep the commander's plan intact. A cheaper deck that does the same thing is a better deck.
What the Free plan covers
Every plan includes the full deck builder, format legality checks and mana statistics. On the Free plan you get 20 Grover messages, 100 Scry searches (search keeps working with keyword results after that, until your monthly reset) and 10 Tutor recommendation runs a month, plus up to 10 saved decks, an account total that does not reset. Each message you send Grover, including each refinement in Build mode, uses one message, so a first draft plus a handful of refinements fits comfortably. Compare paid plans on plans and pricing when you want more; the numbers there are the current ones.
Frequently asked questions
Can an AI build a legal Commander deck on its own?
It can build a draft that is very close, and the deck builder's Validation tab catches what it misses: an off-identity card, a banned card, a second copy. Treat the draft as a strong starting point that you finish with the legality report open.
Should I trust Grover's rules answers?
Use them as a starting point and verify against the Comprehensive Rules. Grover is a deck-building assistant, not a judge. For a rules-shaped question such as how myriad interacts with Isshin, ask, read the answer, then check the rule it points to before you rely on it at the table.
Do I need to know the format before I ask?
Yes. Name the format in the first sentence of the brief. "A Commander deck" tells Grover to respect singleton, the 100-card size and colour identity; without it, you may get a 60-card list with four copies of something.
How many messages does a first draft take?
One prompt produces the draft in Build mode. Each refinement request after that is one more message. Plan on a few refinements, and save the deck between them so nothing is lost.
Can I start from a deck I already have?
Yes. Import or build the list first, then use the deck's Ask AI tab. Because the deck is attached, questions about cuts, upgrades and the mana base are answered against your actual list.
Start your first draft
Create a free Mana Grove account, open Brew, then Build with AI, and type the brief from step 2. The full deck builder is included on every plan, and the Help Center covers every tab if you get stuck.
Try Grover: Grover, the AI deck assistant. Mana Grove's other AI tools, Scry and Tutor, are on MTG AI on Mana Grove.
