Does the playtester enforce the rules of Magic?

No, and that is deliberate. There is no stack, no priority, no mana costs checked and no legality enforcement — you move cards wherever they need to go and the board trusts you. That is what makes it fast enough to actually use: testing whether a deck functions on curve means playing it out, and stopping to satisfy a rules engine every turn is what makes people give up halfway through. The two things it does do automatically are the ones a person cannot do honestly for themselves: it shuffles, and it deals at random.

Do I need an account to play a deck?

No. Pasting a decklist needs no account at all, and any deck someone has made public opens straight from its link. Signing in adds exactly one thing: your own private decks become loadable too. The board itself is stored in your browser, so a game you leave half-finished is still there when you come back on the same device.

Does this work on a phone?

Yes, and it is not a cut-down version — the phone gets the same board, the same zones and the same actions as the desktop. Touch was treated as the primary input rather than an afterthought, because the existing playtesters in this space are all desktop-first and their mobile complaints are real: hands that sit underneath a phone's system navigation bar, card menus that stop appearing, and drags that never land.

How is this different from the sample hand on a deck page?

They answer different questions. A sample hand is a ten-second mulligan check: deal seven, read them, see the exact odds of opening on enough lands, close the box. The playtester is for the question that comes after — does this deck actually do anything by turn five — which you can only answer by playing the turns out. Both exist on purpose and neither replaces the other.

Can I play a precon without owning it?

Yes. Every preconstructed Commander deck this site tracks can be loaded and played straight from its decklist, which is a genuinely useful way to decide whether a deck is worth buying — or to see what you would actually be facing across the table before you build against it.

Free MTG Playtester

Play a Commander deck out, solo, in your browser. Load a deck link, pick a preconstructed deck, or paste a list — then draw an opening hand and play the turns. Every zone, no rules engine, no account.

Paste a decklist

One card per line, 1 Sol Ring. A Commander header or a *CMDR* tag puts a card in the command zone.

Play a precon

Every preconstructed Commander deck this site tracks, ready to play without owning it.

Two things run the turn for you once the board is up. New turn untaps everything, draws for the turn and empties the mana pool, as one step you can undo in one press. Proliferate adds one of every counter already on the board and invents none — a permanent with no counters is untouched, which is what the word actually means. There is a mana pool for your own arithmetic (nothing checks whether you could pay for anything), a game log of everything that happened, and keyboard shortcuts — press ? for the list.

What it does, and what it deliberately does not

Load a deck and you get a board: a battlefield you can put cards anywhere on, a hand, a library, a graveyard, an exile zone and a command zone, with cards moving freely between all of them. Tap a card to pick it up, tap where it should go. Tap a permanent to tap it. Add counters, make tokens, flip a double-faced card, search your library, put something on the bottom.

Cards move two ways, and both work with a mouse or a finger. Drag a card where it should go — anywhere on the battlefield, or onto the library, graveyard, exile or command zone. Or tap it to pick it up and tap where it belongs, which is the same set of moves without holding anything down. A card you drag somewhere it cannot go flies back to where it started; it never disappears and it never sticks to your finger. Press and hold a card for its full menu, or use the ⋮ button in its corner — both open the same thing.

Cards on a board are small by necessity — a battlefield with fifteen permanents on it has to fit fifteen permanents — so there are three ways to read one. The Cards −/+ control resizes the whole board and remembers your choice on that device. On a desktop, hovering a card shows it enlarged. And on any device, the ⋮ button on a card opens View card, which shows the full card with its rules text, every printing and current prices.

What it does not do is enforce anything. There is no stack, no priority, nothing checking whether you can afford a spell, nothing stopping you from putting a card back in your hand from the graveyard. That is a decision, not a gap. The point of playing a deck out is to find out whether it functions — whether the mana works, whether the draws connect, whether turn five does anything — and a rules engine that interrupts you every turn is how that exercise gets abandoned halfway through. The two things it does do for you are the two you cannot do honestly for yourself: it shuffles properly, and it deals at random.

How to load a deck

There are four ways in and they all reach the same board.

Paste a list. No account, nothing to sign up for. One card per line in the usual 1 Sol Ring form. A Commander section header or a Moxfield-style *CMDR* tag puts a card in the command zone where it belongs; anything else goes in the library.
Open a deck link. Any deck someone has made public plays straight from its link, signed in or not.
Play your own deck. Signing in adds your private decks to the picker. That is the only thing an account changes here.
Pick a precon. Every preconstructed Commander deck this site tracks is loadable, which is a cheap way to find out whether one is worth buying before you buy it.

The library is the real library

The deck you load is expanded card for card — thirty basics are thirty cards, not one row with a number beside it — and your commander starts in the command zone rather than in the ninety-nine, exactly as it does at a table. That matters more than it sounds: a playtester that quietly shuffles the commander into the deck, or that treats a stack of basics as a single card, gives you draws that could never happen and quietly flatters the deck. The count in the corner is the number of cards actually left to draw.

Your board is saved on this device

A game in progress is kept in your browser, so closing the tab halfway through a turn does not lose it. It is stored locally and never uploaded — which also means it does not follow you to another device, and a private window will forget it when you close that window. Starting a new game replaces it.

Where this fits with the other tools

The mana base calculators answer a question with a number: given this many sources, how often do I cast this on curve? That is the right question when you already suspect a problem and want it quantified. Playing the deck out answers the question that comes before it — whether there is a problem at all, and which turn it shows up on. If a game here keeps stalling on lands, the mana base calculator will tell you exactly how many sources you are short.