How many poison counters lose the game?

A player with ten or more poison counters loses the game immediately, as a state-based action. This is true in every format including Commander, where the 21-damage commander rule does not change the poison total of ten.

What is the difference between infect and poison?

Infect is a keyword on creatures that deal damage to players as poison counters instead of life loss. Poison counters are the counters themselves. Wither deals damage as -1/-1 counters to creatures but does not poison players, so it is tracked separately.

How does proliferate interact with poison?

Proliferate lets you add one more of each counter type already present. For poison, every player who has at least one poison counter gains one more. This tool's proliferate button does exactly that, skipping players still on zero.

Does infect combat damage also reduce life?

No. Infect changes all damage that source would deal, so a creature with infect deals its damage entirely as poison counters to players, with no life loss. Against creatures it deals -1/-1 counters instead. The two damage types never stack on the same hit.

Can a single counter be removed?

Some effects remove poison counters, though they are rare. Use the minus button to correct an over-count or to apply a removal effect. The tracker never lets a total fall below zero.

What is the MTG Infect / Poison Counter Tracker?

Track poison counters for each player toward the 10-counter loss in Magic: The Gathering, log infect combat and proliferate, and see exactly how many more poison counters each player can take before losing. It runs free in your browser on Gera Tools, with nothing uploaded.

MTG Infect / Poison Counter Tracker

Name: MTG Infect / Poison Counter Tracker
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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Infect decks win by stacking ten poison counters on an opponent rather than reducing life to zero — a completely separate threshold that runs in parallel to the normal 20-life game state. This tracker keeps each player’s poison total, handles proliferate, and shows how many counters remain before each player loses, so nothing gets miscounted during a fast infect sequence.

How it works

The rule is simple and absolute: a player with ten or more poison counters loses as a state-based action. The tool models each player’s poison count and never lets it fall below zero:

remaining to lose = max(0, 10 − poison counters)
loss triggered    = poison >= 10

Proliferate adds one counter to every player who already has at least one poison counter, matching the keyword’s exact wording. The tracker’s proliferate button skips any player still on zero, since they have no poison counter of that type to add to.

Infect vs. wither vs. poison — what to track

Source	Effect on players	Effect on creatures	Track here?
Infect creature	Poison counters	-1/-1 counters	Yes
Wither creature	Nothing	-1/-1 counters	No
Proliferate	+1 to existing counters	—	Yes
Direct poison effects	Poison counters	—	Yes

Only infect damage to players and direct poison effects add to this tracker. Wither damage to creatures and infect damage to creatures (which deal -1/-1 counters) are irrelevant here. Some cards specifically say “that player gets a poison counter” — those go here too.

Multiplayer and Commander notes

In Commander (and all other formats), the poison threshold is ten — not reduced or scaled by player count. The 21-point commander damage rule is a completely separate loss condition. A player can simultaneously be at risk from poison, commander damage, and normal life loss; this tracker handles only the poison side.

Proliferate is especially strong in multiplayer: with three opponents each on four or more poison counters, a single Contagion Engine activation moves all three closer to ten at once. Use the batch-add input for a large unblocked infect swing (for example, an 8-power infect creature connecting on an open board adds 8 to that player in one tap) rather than tapping the plus button eight times.