Pick a deck builder by what you will actually do with it: check that it supports Commander's rules as you build, shows what a free account includes in numbers, imports and exports your lists, and is clear about ads and your data. Then try one real deck in it before you commit. The nine checks below take about ten minutes.
Each check is a question you can answer from a builder's own pages. The examples come from Mana Grove, the free MTG deck builder that publishes this guide; hold any tool, ours included, to the same standard.
Does it check Commander's rules while you build?
A good builder checks the rules every time the list changes. For Commander, that's five things:
- 100 cards, commander included (Comprehensive Rules 903.5a; with partners, 702.124b).
- One copy of each card, except basic lands and cards whose own text allows more (rules 903.5b and 113.6n).
- Colour identity: every colour in a card's identity, which counts the mana symbols in its rules text too, must appear in your commander's (rules 903.4 and 903.5c).
- The ban list, which the Comprehensive Rules don't contain: they leave a card's format legality, "including whether it's banned or restricted", to separate documents (rules 100.6 and 113.6n), so the builder must keep the format's published list current.
- Game Changers, a published list of cards that can dramatically warp a game: Brackets 1 and 2 exclude them, Bracket 3 allows up to three, and Brackets 4 and 5 have no limit.
Test it by adding a second copy of a card. In Mana Grove, the Validation tab checks deck size, copy limits, the commander, colour identity and card legality, and names the card behind each problem. The deck builder also counts your Game Changers and shows your list's bracket as you build. How to build a Commander deck explains each rule.
What does the free plan include, in numbers?
"Free" should come with numbers: messages, searches, saved decks, collection size, and what happens at each limit. "Limited" isn't a number. Find the numbers on the pricing page before you sign up.
Mana Grove's Free plan includes the full deck builder, legality checks and mana statistics, plus 20 Grover messages, 100 Scry searches and 10 Tutor recommendations a month. Your account holds 10 saved decks and a 1,000-card collection, totals that don't reset. When an allowance runs out, that feature pauses until your monthly reset, except search, which carries on with keyword results; your decks and collection are never touched. Allowances and limits has the details.
Can you get your decks in and out?
Paste a list in, then export it in the formats you use: plain text, CSV, and the MTG Arena and Magic Online (MTGO) formats. Do both on day one, before a builder holds hours of your work.
Mana Grove imports a pasted or uploaded decklist in plain text, with or without set codes and headings such as Commander and Sideboard, or as CSV or JSON. It exports a deck as plain text, CSV, JSON, MTG Arena, MTGO, a .dec file, its own lossless format, PNG or PDF.
Can it find cards by what they do?
Name search is the easy part. Describe a job instead, such as "a board wipe that spares my own creatures", and see whether the cards that do it come back, narrowed to your commander's colour identity. Try a search whose answer you already know.
Mana Grove's Scry takes a plain-language description in the card catalog or inside the deck builder, and the filter sidebar narrows by colour identity, mana value or card type. Getting Better Search Results has more examples.
Does it know your collection?
If you build from what you own, the builder should import your collection, show which cards in a deck you have, and search only your cards when you ask.
Mana Grove imports a collection from a CSV or another tool's export and exports it as CSV, JSON, plain text or the Mana Grove format. It marks the cards you own in every deck, and search has a Collection Only switch. Tutor's suggestions read your collection too. The Free plan holds 1,000 cards, every copy counted; collection statistics come with the paid plans.
Does its help explain itself and say when to check the rules?
Look for a reason on each suggestion, a legality report that names the problem and the card, and an assistant that quotes the rule and tells you to check it. Guides should cite the Comprehensive Rules by number.
In Mana Grove, each Tutor pick carries a synergy score, and most name the reason, such as a card in your deck it pairs with. When Grover looks up a rule, the chat quotes it with its number, and Grover's help page calls its rules answers a starting point to verify. The bracket checker tags every reason Published policy or Mana Grove's reading, and our guides cite rule numbers, as this one does.
Are the prices on the page, with currency and tax?
You should see the amount, the currency and whether tax is included before you sign up. If finding a price means starting a checkout, keep looking.
Mana Grove's pricing page shows every plan in Canadian dollars, US dollars, euros and pounds. Canadian and US prices are before tax, euro and pound prices include VAT, and an annual plan costs 12 months for the price of 10.
Does it show ads, earn from store links or sell your data?
A free tool is paid for somehow: ads, store links that pay per sale, sponsored suggestions or your data. Read the terms, not just the homepage, and check that you can export and delete your data.
Mana Grove answers in section 11 of its Terms of Service: no ads on the product, no affiliate links and no selling of your personal data, permanent commitments that a routine terms update can't change. Recommendations are never sponsored, and subscriptions are the only revenue. Your data export and account deletion are both in Settings.
Does it work where and how you play?
Open the builder on the device you'll have at the table, usually a phone. Then check that it speaks your language and that you can subscribe where you live.
Mana Grove runs in the browser on a computer or a phone, with nothing to install, in English and French. You can subscribe in Canada, the United States, the United Kingdom and the 27 EU member states; players elsewhere can join a waitlist.
The nine checks on one page
Print it, or keep it open while you try a builder.
| # | Check | How to test it | A clear answer |
|---|---|---|---|
| 1 | Commander's rules as you build | Add a second copy of a card | Flagged at once, card named |
| 2 | The free plan in numbers | Read the pricing page | Every limit as a number |
| 3 | Decks in and out | Paste a list, then export it | Plain text, CSV, MTG Arena and MTGO |
| 4 | Cards by what they do | Describe an effect you know | The cards you expected |
| 5 | Your collection | Import your collection file | Owned cards marked as you build |
| 6 | Help that explains itself | Read a suggestion and a rules answer | A reason, a rule number |
| 7 | Prices with currency and tax | Open the pricing page signed out | Amount, currency, tax |
| 8 | Ads, store links and your data | Read the terms of service | All three answered in writing |
| 9 | Where and how you play | Open it on your phone | Your browser, language and country |
Where Mana Grove fits, and where it does not
Mana Grove is a free MTG deck builder for Commander, built in Canada. It's a fit if you play Commander, want the rules checked as you build, want to ask an assistant in plain language, search cards by what they do and build from the cards you own, with no ads.
It's not the right fit if you need an app from an app store, a card scanner or a place to buy and sell cards: Mana Grove does none of these.
Frequently asked questions
Is a free deck builder enough for Commander?
For building and checking decks, yes, if the legality checks and mana statistics are free. In Mana Grove they're on every plan. Paid plans add room, not rules checks: more Grover messages, unlimited Scry searches, more Tutor runs, more decks and collection space, and collection statistics.
Do I need an AI deck builder?
No. You can add every card yourself, and the rules checks work the same. An assistant helps when you want a first draft from a short description or a second opinion on cuts. Grover, the AI deck assistant shows what one drafts, and you can try it in the Grover demo without an account.
Can an AI build a legal Commander deck?
It can draft one that comes close, and a legality check catches the rest: a card outside your colour identity, a banned card or a second copy. In Mana Grove, the Validation tab checks every deck the same way, whoever built it.
Does Mana Grove work in French?
Yes. The deck builder, the pricing page, the help pages and the guides are in French under /fr, and you can describe the deck you want to Grover in French. The French guides are machine translations of the English ones.
Try one real deck
Pick a commander you know, build the deck you'd actually bring to the table, and run the nine checks as you go. In Mana Grove, start in the deck builder demo without an account, then create a free account to keep the deck. Plans and pricing lists every allowance.
Try Grover: Grover, the AI deck assistant. Mana Grove's other AI tools, Scry and Tutor, are on MTG AI on Mana Grove.
Sources
- Comprehensive Rules, effective September 25, 2026, rules 100.6, 113.6n, 702.124b, 903.4, 903.5a, 903.5b and 903.5c: https://magic.wizards.com/en/rules. Read on October 26, 2026. The construction rules and the pointer to separate rules that limit cards.
- Commander format page, Brackets and Game Changers sections: https://magic.wizards.com/en/formats/commander. Read on October 26, 2026. What a Game Changer is and how many each bracket allows.
- Mana Grove pricing page, read on October 26, 2026: the Free plan allowances, the four currencies and how tax is shown.
- Mana Grove Terms of Service, sections 11.1, 11.2, 11.4 and 11.6, read on October 26, 2026: the permanent commitments and how they can change.
We update this guide when the plans or the rules change. The date at the top is the last revision.
