Pointed Discussion

The only point I see in this card is in a two-colored deck with tons of creature removal, where you keep your opponents table clean of creatures.

This card is suck! Unless you also have a celestial dawn in play... hmm.

I don't blame you people for going dyslexic on this card. Let me illustrate for any who may be confused, for example: Two Fusion Elementals will each get +10/+10. This card is obviously meant for a multicolored deck, not mono.

Except, mrredhatter, it says "as long as the ALL share a color". Doesn't that imply that, in order to get the +2/+2 boost, ALL creatures IN PLAY must share a color? Plus, if they meant that all creatures get +2/+2 for each color they share, then it should be worded as such. As it is written now, Common Cause is really sub-par, unless in a mono-color deck. I might be wrong on all this, but it seems to me that you're mis-interpreting the rules text of the card.

EDIT And now that the Oracle is back, if ONE creature on ANY SIDE of the board is a different color from the rest...the effect is lost. Thus, it really is a sub-par card. Celestial Dawn, Painter's Servant, and any card that changes creature color on a global scale will work with this card, but even then, your opponents get the bonus as well.

Kind of a lame card, in my opinion.

Mrredhatter is wrong; this card doesn't do anything nearly that cool.

Hmmm... Hour of Reckoning, perhaps? Or maybe Martial Coup? Leave Common Cause on the field for a few turns, build up an a few tokens, then wipe the board and swing through with your army of 3/3s?

Otherwise, Thran Forge or Neurok Transmuter would both stop opponents creatures from counting towards your +2/+2 bonus. It's not a good combo, but it would make your opponent go lol.

Mrredhatter is often wrong.

This does not seem like a good card. If your opponent plays any creature that isn't the same color as yours, yes even just one, you have an enchantment that does nothing. If you are playing against an opponent running creatures that all share one color, then chances are they are also playing a creature-heavy aggro deck except they will run non stupid cards that only affect their creatures, like glorious anthem or honor of the pure or marshal's anthem.

Although, it would be funny in multiplayer when everyone groups up on whoever is off color.

It only works well in a deck that can control the table with creature removal!

Painter's Servant. Pick purple or something.

Only good if you have more or better creatures than your opponent while they're playing the same (single) color as you, or else they have no creatures at all (whether by their choice or your removal).
Yah, pretty narrow.

the sad thing about this card is, the stupid word 'all' and how it used to be applied.
first, you can see that the first word on the card as it SHOULD be read is really a hidden 'all'- so it's 'all non-artifact creatures blah blah blah'

second, that immediately shows that whatever you are supposed to do with this card, you need to make sure you load up on one-sided Wrath effects, since I have never seen a deck that that ran only artifact creatures in the creature section-- even Affinity had the Disciple of the Vault, and looking back to ancient Magic days, if they WERE running a creatureless deck or a deck whose creatures were only artifacts, you'd be looking at super-uber shit like Mishra's Workshop and the like. Could you hope they are running Darksteel/Blightsteel + Tinker Combo?....why would you WANT them to?
the stuff against which this works is 10x better than this itself, even if Mr. Red Hatter is right about Fusion Elementals, because trying to power those guys out off of Moxen and Lotuses seems...uh...a massive waste of Power?

the only way I can see this being useful at all is in multiplayer, purely because those games are better for trying to set up convoluted niche situations, which this card is literally the Lord of.

A sideboard card against creatureless decks that only works for mono-white. Maybe the narrowest card ever.

Well, no. Great Wall is the narrowest card ever, but this was printed in Mercadian Masques. They were supposed to know better than the people who came up with Great Wall.

Removal heavy token deck?

Rulings:

"It really does mean "all creatures", including your opponent's. Yes, the card really does suck that much. We had to scale back after all those crazy combo decks..."

it has "common" in its name.
it's rarity is "rare"
it's rating is worse than many other "common" card (for good reason)
..i rate it with 1whole star only because it is "rare" to see a so useless card.

Angered by their exclusion, the artifact cards went into hiding, returning triumphantly many years later with Tempered Steel.

They went on to beat the crap out of people with 2/4 Ornithopters and 3/3 Memnites.

This card is too unstable and effectively useless without a combo.

I wouldn't even start to try solving that problem with removal.
Once you reach the point where you can reliably control what's on your opponent's side of the field,
there won't be any creatures left on yours to profit from this enchantment.

Instead, try to make sure the condition is true no matter what by altering all creatures' colors.
Darkest Hour or Painter's Servant would work.