What is infect?Creatures with infect deal damage to players and creatures in different ways than other creatures.
This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.
You've probably heard of +1/+1 counters. Creatures like Feral Hydra can put +1/+1 counters on themselves. An infect creature deals damage to creatures in -1/-1 counters instead of just dealing normal damage. So suppose an 2/2 infect creature like Contagious Nim attacks. If the other player blocks with a 3/3, then instead of nothing happening when Contagious Nim deals its damage, it puts two -1/-1 counters on the 3/3 creature instead of dealing 2 damage. So now, the 3/3 creature is only a 1/1 creature! This makes infect very deadly indeed. Not only is the creature weaker permanently, but it gives the creature -1/-1 instead of -0/-1! Another extremely deadly part of infect is that it deals poison counters to players. Normally, if a 2/2 creature attacks, and the opposing player lets the damage go through, that player would simply lose 2 life. But with infect, the player would get 2 poison counters instead. Here's the important thing: a player with 10 or more Poison counters loses the game! And there's one way to get rid of poison counters, Leeches!