Winter Orb
In the first versions of the Magic rules, the static abilities of an artifact turned off if the artifact was tapped. When this rule changed, three cards (Winter Orb, Static Orb, and Howling Mine) were issued errata to maintain this functionality. Since then, Static Orb and Howling Mine have been reprinted with this errata, but Winter Orb never was. If you pick up this card somewhere and you understand modern Magic rules, you'd never guess it would have to be untapped to function, and the once-common "tap my own Winter Orb at the end of my turn so I get to untap my lands" play would be utterly baffling. Well, we can't have that.
New wording
Players can't untap more than one land during their untap steps.