Cheapest priced copy (Modern Masters): $0.35 at Card Kingdom, near mint, their price list as of .
Tromp the Domains 
Sorcery · Uncommon · Time Spiral Remastered · #242
Domain — Until end of turn, creatures you control gain trample and get +1/+1 for each basic land type among lands you control.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Modern Masters | 171 | Uncommon | $0.35 | $0.49 |
| Time Spiral | 230 | Uncommon | $0.35 | $0.49 |
| Time Spiral Remastered | 242 | Uncommon | $0.35 | $0.49 |
4 rulings from Wizards of the Coast
- 19 March 2021The size of the bonus is determined only as Tromp the Domains resolves. Once that happens, the bonus won't change later in the turn even if the number of basic land types among lands you control changes.
- 19 March 2021Tromp the Domains affects only creatures you control at the time it resolves. Creatures you begin to control later in the turn won't gain trample or get a power and toughness boost.
- 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.
- 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.