Counters

[Lunis22]

Do counters of opposite types cancel each other? For example putting a +1/+1 counter on a creature with a -1/-1 counter.

[Pleeb]

The end result is they cancel each other, but they don't remove each other. You can have +1/+1 and -1/-1 counters on a creature at the same time.

[Millionlittlee]

The end result is they cancel each other, but they don't remove each other. You can have +1/+1 and -1/-1 counters on a creature at the same time.

Actually they do remove each other. You can't have both.
If you have 3 +1/+1 counters, and it gets 2 -1/-1 counters on it it ends up with 1 +1/+1 counter

[Keyeto]

The end result is they cancel each other, but they don't remove each other. You can have +1/+1 and -1/-1 counters on a creature at the same time.

Actually they do remove each other. You can't have both.
If you have 3 +1/+1 counters, and it gets 2 -1/-1 counters on it it ends up with 1 +1/+1 counter

This is true. The smaller number of counters are removed:

121.3.: If a permanent has both a +1/+1 counter and a -1/-1 counter on it, N +1/+1 and N -1/-1 counters are removed from it as a state-based action, where N is the smaller of the number of +1/+1 and -1/-1 counters on it. See rule 704.

[Millionlittlee]

I feel victorious i beat you to the answer. Lol

[Millionlittlee]

On this note, this is why sticking a {Glistening Oil} on your {Protean Hydra} is so much fun

Edit: Found it XD

Any hydra is good with that card