Several world enchantments, sometimes a cycle.
Cycle of wedged-colors. (eg
At the beginning of each player’s upkeep, that player sacrifices a permanent. If he or she doesn’t, that player discards a card. Then, ~ deals damage equal to the converted mana cost of the permanent sacrificed or card discarded this way to each player. Then, that player gains life equal to the damage dealt this way.Biodome
Creatures with one or more +1/+1 on them counters have haste.
Creatures with two or more +1/+1 on them counters have mindlink. (Whenever this creature deals damage to an opponent, its controller draws a card.)
Creatures with three or more +1/+1 on them counters have trample.
Creatures with four or more +1/+1 on them counters have flying and first strike.
Creatures with five or more +1/+1 on them counters have shroud and vigilance.Realm of Eternal Bliss
Any player may cast ~ from the exiled zone.
When ~ enters the battlefield, put all cards in the exiled zone into their owner's graveyard.
If a card would be exiled, put it into its owner's graveyard instead.Stratosphere
Creatures with flying have haste and protection from creatures without flying.
Creatures without flying lose haste and can’t attack unless their controller pays
for each creature he or she controls that’s attacking.Jurassic Park
At the beginning of your upkeep, each player displaces three cards. Then, each player may put a permanent card in any graveyard into play under his or her control.