# Does a +1/+1 counter remove a -1/-1 counter?

My opponent controls a Kulrath Knight. I control a 4/4 creature (with a -1/-1 counter on it, due to an earlier cast Black Sun's Zenith).

If I use an ability to put a +1/+1 counter on my 4/4 creature, will the +1/+1 counter and the -1/-1 counter cancel each other out, or will I just have a creature with both a +1/+1 counter and a -1/-1 counter on it?

In other words: Will my creature be able to block and attack or not?

I don't believe the rules are 100% clear on that?! (rule 704,5)

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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.

Both counters will be removed as a state-based action (N=1). Your creature will be able to block and attack.

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Seems like a bad ruling. Say for example I have a Tetravus, which comes into play with three +1/+1 tokens. My opponent places three -1/-1 tokens on it. At the beginning of my next upkeep, I should be allowed to remove all three +1/+1 tokens - in effect sacrificing the creature. I wouldn't be able to do this if these tokens had been neutralized by the -1/-1 tokens. – primo Jun 14 '14 at 14:07
@primo: "because it would make my creature bad" is not a reason that a ruling is bad. If somebody does something that neutralises a creature, well that's kind of what magic is about. Finding ways to counter the powers of other creatures. And the rules seem pretty clear so its not the ruling that you should be complaining about but the rule itself. – Chris Jun 14 '14 at 14:54
@Chris "its not the ruling that you should be complaining about but the rule itself." Indeed, that was my intention. Consider a creature with a +2/+2 enchantment and a -2/-2 enchantment; they do not neutralize one another, both remain. What makes tokens different? Unless both tokens originated from the same source, or an abilty specifically states, 'place a -1/-1 token, or remove a +1/+1 token', I don't think they should be considered the same. It would be interesting to know when exactly this rule was added. – primo Jun 14 '14 at 15:14
@primo I think that the reason a special case was made for +1/+1 counter and -1/-1 counters is because counters in general are supposed to serve as "reminders" to players. Once a creature has a +1/+1 and a -1/-1 counter, the player no longer needs to be reminded, and so they disappear. Other types of counters are less common, or can't really "cancel" in any mathematically satisfying way, and so they don't. Players probably don't need to be reminded of enchantments because the words are literally written on them. Please don't quote me on any of this, because I can't back it up. – Rainbolt Jun 14 '14 at 22:29
@primo You're correct that there is complexity in both cases, but in one, the complexity is one-time: The first time you add an opposing counter to the existing one and encounter this rule. The alternative is continual complexity: every time I look at your creature, I have to add, subtract, and work out its current P/T, whether it will Persist etc. Continual complexity is more problematic than "on-effect" complexity. – deworde Jun 17 '14 at 12:50

Here's the text of the relevant rule:

704.5r 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, where N is the smaller of the number of +1/+1 and -1/-1 counters on it.

It's supposed to be pretty clear: if your creature has one +1/+1 counter and one -1/-1 counter on it, you remove one +1/+1 counter and one -1/-1 counter from it, leaving it with no counters. (One is the smaller of the numbers one and one.)

And then in the specific case of Kulrath Knight, yes, your creature will be able to attack and block, since it will have no counters on it.

If you find the "N" part of the rule confusing, you can really just think of it as "they cancel." If there are five +1/+1 counters and three -1/-1 counters, N is three (the smaller of five and three) and so you remove three of each. If there are one of each, then N is one (the smaller of one and one), and so you remove one of each. In every case, you're canceling out "as many as possible".

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Well it was the N part that confused me. Since the smaller number of one and one is...both?... None? Anyways wouldn't it be even clearer to say that a +1/+1 counter and a -1/-1 one counter cancel each other out? But thanks for making it clear for me! :) – Lund Jun 13 '14 at 19:08
@user7268, 1 is the smallest of the numbers 1 and 1. ("Both" and "none" aren't even numbers.) – ikegami Jun 13 '14 at 19:09
N syntax to refer to quantities can be confusing to some people, especially for those without a strong foundation in a math-heavy background. Seems like a completely reasonable thing to get clarification on. – Ellesedil Jun 13 '14 at 19:11
@Ellesedil Which is why I clarified it. I just wasn't sure which part was confusing. And indeed, it wasn't the N that was confusing. It was the idea of taking the minimum of two equal numbers. – Jefromi Jun 13 '14 at 19:18
@user7268 They're trying to avoid having to apply state-based actions multiple times (instead of "cancel one counter, then cancel one more, then...", "cancel N"). – Jefromi Jun 13 '14 at 19:19