Cheapest priced copy (The List): $14.99 at Card Kingdom, near mint, their price list as of .
Collective Restraint 
Enchantment · Rare · Invasion · #49
Domain — Creatures can't attack you unless their controller pays {X} for each creature they control that's attacking you, where X is the number of basic land types among lands you control.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
2 printings · $14.99 to $94.99 at Card Kingdom
4 rulings from Wizards of the Coast
- 1 February 2007In the Two-Headed Giant format, you still only have to pay once per creature.
- 1 February 2014Unless some effect explicitly says otherwise, a creature that can't attack you can still attack a planeswalker you control.
- 18 June 2021The basic land types are Plains, Island, Swamp, Mountain, and Forest. Land types other than basic land types (such as Desert) don't contribute to domain abilities.
- 18 June 2021Domain abilities count the number of basic land types among lands you control, not how many lands you control or how many of any type.