Infect vs toxic in Magic: damage and poison counters
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Infect and toxic both produce poison counters, but they calculate their results differently. Infect changes the consequences of damage: a player gets poison instead of losing life, while a creature gets −1/−1 counters. Toxic N adds N poison counters when the creature deals combat damage to a player, without replacing ordinary damage.
In an ordinary game, a player with ten or more poison counters loses. Gaining life does not reduce that count. To resolve an interaction, separate how much damage is dealt, who receives it and which ability the source actually has.
Comparing hypothetical 3/3 creatures
Imagine three hypothetical 3/3 creatures dealing three combat damage to a player, without prevention or other effects. One has infect, one has toxic 1 and one has toxic 2. Their power is identical, but the resulting poison counts are different.
| Ability on the 3/3 | Life lost as a consequence of that damage | Poison counters received |
|---|---|---|
| Infect | None | 3 |
| Toxic 1 | 3 life | 1 |
| Toxic 2 | 3 life | 2 |
| Infect and toxic 2 | None | 5: three from infect and two from toxic |
The comparison assumes all three damage reaches the player. If prevention reduces it, or the creature never damages that player, recalculate. Printed power alone is insufficient once blocking, modifiers or prevention change the actual damage event.
The final row shows that both abilities can coexist. Infect determines how the damage affects the player, and toxic adds its poison amount for combat damage. You do not choose one and discard the other simply because both abilities refer to poison.
Infect damage to players
Damage from a source with infect does not cause a player to lose life through the ordinary damage result. Instead, that player receives the same number of poison counters. Four actual damage produces four poison counters; one damage produces one. The calculation still follows the amount dealt.
Infect is not restricted to combat damage. It can also modify noncombat damage dealt by a source with infect. Identify the actual source of that damage rather than attributing a creature's ability to every spell or effect that happens to involve the creature.
For example, if an ability instructs a creature with infect to deal two damage to a player, that creature's damage produces two poison counters. If a separate spell deals the two damage itself and lacks infect, a creature standing on the battlefield does not automatically lend the spell its ability.
Distinguish damage from life loss as well. An effect saying a player loses life is not necessarily dealing damage. Infect does not convert every reduction in life into poison, and it does not alter life paid as a land activation or another cost.
Toxic damage to players
Toxic N adds the specified number of poison counters when the creature deals combat damage to a player. The damage retains its normal consequences, including life loss in the usual case. The toxic value does not replace power and is not multiplied by power.
A 5/5 with toxic 1 dealing five combat damage normally causes five life lost and one poison counter. A 1/1 with toxic 3 dealing one damage causes one life lost and three poison counters. These are hypothetical examples separating the quantities, rather than descriptions of particular printed cards.
Wizards sets out the interaction in the official Phyrexia: All Will Be One release notes. The relevant condition is combat damage to a player. An ability dealing damage outside combat does not award toxic's counters merely because its source has toxic.
Multiple instances of toxic add their values together. Toxic 1 and toxic 2 produce three counters when toxic applies. Do not choose only the larger instance, and do not assume an effect granting toxic replaces an existing instance without reading what the effect says.
Damage to creatures works differently
Infect deals damage to a creature in the form of −1/−1 counters. Those counters change power and toughness and do not disappear when marked damage is cleared at the end of the turn. A creature can die when its toughness becomes zero or less, depending on the game state.
A 3/3 with infect dealing three damage to a 4/4 ordinarily leaves three −1/−1 counters on it. Without other effects, it becomes a 1/1. The reduction remains while the counters remain; it is not simply marked damage that disappears during cleanup.
Toxic does not produce that result against creatures. A 3/3 with toxic 2 dealing three damage to a 4/4 does not give it poison or −1/−1 counters through toxic. It deals damage normally, and the poison ability does not apply because the recipient is not a player.
Do not transfer the creature rule automatically to other permanents. Infect defines particular damage results for players and creatures; damage to a planeswalker or battle follows the corresponding rules. Identifying the recipient matters just as much as recognising the keyword on the source.
Blocking, trample and prevention
If a toxic creature is blocked and damages only its blocker, the player receives no poison from toxic. Declaring the attack is insufficient. The creature must actually deal combat damage to the player before toxic contributes its counters.
With trample, check how much combat damage actually reaches the player. Any positive amount allows toxic to apply its full value, rather than a proportional fraction. A creature with toxic 2 that manages to deal one combat damage to the player still adds two poison counters from toxic.
Infect instead scales with the damage that player receives. If only one damage from the infect source reaches them, that produces one poison counter. Damage dealt to the blocker has infect's creature consequences; it is not added to the player's poison total.
If all damage to the player is prevented, there are no infect counters from that prevented damage and no toxic counters associated with dealing combat damage. An announced attack does not generate poison on its own. Resolve prevention before updating the counter total.
Double strike and power changes
A creature with double strike can deal damage in two combat-damage steps. If it damages the player in both, toxic applies on each occasion. A toxic 1 creature can therefore give one poison counter in the first step and another in the second, provided both damage events actually happen.
Do not assume the second event is guaranteed. The creature can leave combat or the position can change between steps. Double strike determines participation in the damage steps; your calculation must follow the events that occur rather than the events you expected when attacking.
Increasing power can increase poison from infect because it can increase the damage dealt. It does not increase a toxic value by itself. Turning a toxic 1 creature from 1/1 into 4/4 can increase life loss while retaining one poison counter for each relevant damage event.
The distinction also matters when damage is reduced. Toxic keeps its fixed amount if positive combat damage still reaches the player. Infect produces fewer counters if actual damage decreases. Two poison strategies can consequently value the same power-changing effect differently.
For tracking purposes, announce the damage amount and poison amount separately. “Three damage, two poison from toxic” is clearer than saying only “two poison,” especially if life loss or another damage-related ability also matters. Clear communication prevents one ability from hiding the other consequences of the event.
Poison, life and Commander
Keep poison separate from life. Counters received from several sources accumulate on the same player. Do not reset the number because the attacking creature changes or because another opponent deals the next damage in a multiplayer game.
Ordinary Commander also uses ten poison counters as the loss threshold, despite its different starting life total. Twenty-one combat damage from one commander is a separate condition with its own record. It does not replace the poison threshold or turn poison into a twenty-one-counter rule.
Combat damage from a commander with infect remains combat damage from that commander even though it does not cause ordinary life loss. It can matter for both records. Looking only at the change in life is therefore insufficient to measure commander damage received.
Proliferate can increase existing poison counters under its rules, but it does not automatically poison a player with no such counter. Likewise, life gain does not remove counters. Read an effect specifically if it claims to modify or remove counters rather than inferring that ability from its theme.
Frequently asked questions
Does toxic work when a creature deals damage through an ability?
Not through that damage, because toxic requires combat damage to a player. Infect can modify noncombat damage when its actual source has infect. Identify both the real source and the type of damage before applying either keyword.
Does a power boost increase toxic's number?
Not automatically. Toxic uses its own value, while power can change damage. The creature must still deal combat damage to the player; if it does, add the toxic amount it has at that time rather than substituting its power.
Will life gain save me at ten poison counters?
Not in an ordinary game. Life and poison are separate records, and gaining life does not remove those counters. At ten or more, the poison loss condition applies regardless of whether your life total remains high.