Normally I play with a little system I came up with called "Arrows". Basically, whenever you do something bad to me (attack me, blow up one of my permanents, etc.), you get an Arrow. An Arrow is a token-like card (with an Arrow on it) that I put on the table pointing at you. This means I owe you a beating.
Arrows are not permanents and do not directly affect (or are affected by) the game. They are simply my way of indicating who I'm mad at. When it's my turn, the current Arrow determines who I give my retribution to for the turn. In the case of multiple Arrows, they are first-in, last-out (like the stack). So the most recent person to hurt me gets hurt back.
If no one has an Arrow, I usually just attack the person with the highest life or the best board state.
Ways to get an Arrow:
  • If you attack me, it's an Arrow. Doesn't matter if the attack succeeds or how much damage it is. If someone else Fogs, you still get the Arrow, because you did try to hurt me. If you are attacking me with a creature that cannot possibly do damage (Solemn Simulacrum into a huge blocker, etc.), I usually don't give the Arrow.
  • Each card that is destroyed, exiled, stolen, or neutered (e.g. Imprison in the Moon) is an Arrow. Yes, wrathing my board generates a lot of hate from me. Tokens don't count, even if there was 100 of them.
  • Direct damage (burn): Each 5 direct damage to me within a turn is 1 Arrow. If you do 4 or less, it's nothing.
  • Bouncing cards: Divide the number of cards you bounced by 2, rounded up. This is how many Arrows you get. Note that bouncing one card is an Arrow. Again, Tokens don't count.
  • Countering one of my spells is an Arrow. This means I may attack you immediately, as it's probably my turn.
  • Discard is not an Arrow unless you make me discard my whole hand, at which point it's 1 Arrow. Wheel of Fortune (discarding and refilling my hand) is not an Arrow.
  • Mill is not an Arrow unless you mill my entire library, which is an Arrow (probably not relevant because I'm likely dead!)
  • Preventing me from doing things (Stasis, Iona, etc.) is an Arrow for each turn I can't act or do what I want. This includes protecting the player who has the current Arrow. Mindslaver is an Arrow, but if you wreck my stuff while you control my turn, you will get more.
  • Removing Arrows:
  • When I attack you, I remove an Arrow. While I'm attacking you, if you destroy one or more of my creatures (or other permanents), I don't give additional Arrows, because you are simply "protecting yourself". You are in a sense immune to Arrows while I'm attacking you.
  • I remove an Arrow for each card I destroy. Basically, if I do anything that would cause an Arrow (above), I clear the same number of Arrows on you.
  • If I cannot affect the player with the current Arrow at all, I usually just pass (and wait for next time). I don't usually attack the next player in the stack. I automatically clear one Arrow at the end of my turn if I did nothing.
  • You cannot bribe me or do favors for me to remove Arrows. I hate you for what you did. You need to die.
  • If someone dies, (obviously) all the Arrows pointing at him are removed from the Arrow pile.
  • Arrows do lots of cool things:
  • People don't complain that I'm "targetting them". If you have an Arrow, you deserve your beating.
  • Arrows seem to work as a deterrent to people trying to hurt me or my board state. Sometimes people fear the Arrow, and will not attack me, because they know they will be hurt back.
  • Other special cases for Arrows:
  • Sometimes (especially when it's after 2 AM!) I'm too tired to properly play Arrows. Complaining about me not following the Arrow rules properly is likely to get my ire!
  • If you cast the card Twiddle (must be this exact card by name), you may "turn" an Arrow to point to anyone you want. This is a side effect; you still Twiddle something. (You don't Twiddle the Arrow directly; Arrows aren't permanents.) If you Radiate a Twiddle, you can turn any number of Arrows.
  • Attacking me with Grizzly Bears (must be this exact card by name) does not generate an Arrow from me.
  • The card Ass Whuppin' can remove an Arrow, since the actual arrow tokens I use are silver bordered. (This technically shouldn't work, but it's silver border land, so it's OK.)
  • There are weird situations where I have an Arrow pointed at myself. In that case, on that turn I don't attack anyone.
  • Insulting or Trash Talking the Arrows may (or may not) give you an Arrow. Generally, if you are doing it because you want an Arrow (to protect someone else or gain some advantage), you won't get one. So there.
  • This is very rare (about once a month): If I (usually unintentionally) *really* hose one person (destroy all their lands, etc.) and they didn't even have any Arrows, I may give them an "Anti-Arrow". This means they are immune to Arrows and I won't attack them, until they rebuild and/or start to be aggressive to me.
  • Here is what some of the Arrow Tokens physically look like (I have a lot of them). They are the size of a magic card, and have a foily silver border.