Cheapest priced copy (Foundations): $0.99 at Card Kingdom, foil, near mint, their price list as of .
Adaptive Automaton 
Artifact Creature — Construct · 2/2 · Rare · The Brothers' War Retro Artifacts · #1
As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.
Legal inCommanderBrawlStandardPioneerModernLegacyVintage
Not legal inPauper
8 printings · $0.99 to $7.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters | 231 | Rare | $2.49 | $2.49 |
| The Brothers' War Retro Artifacts | 1 | Rare | $1.99 | $2.49 |
| The Brothers' War Retro Artifacts | 64 | Rare | $2.79 | $2.49 |
| The Brothers' War Retro Artifacts | 64z | Rare | — | — |
| Explorers of Ixalan | 42 | Rare | $2.49 | — |
| Foundations | 723 | Rare | — | $0.99 |
| Magic 2012 | 201 | Rare | $2.49 | $4.49 |
| Secret Lair Drop | 1109 | Rare | $6.99 | $7.99 |
3 rulings from Wizards of the Coast
- 8 November 2024Even though Adaptive Automaton is a Construct, other Construct creatures you control won't get +1/+1 unless you chose Construct as Adaptive Automaton entered the battlefield.
- 8 November 2024The choice of creature type is made as Adaptive Automaton enters. Players can't take any actions between the time the choice is made and the time the appropriate creatures begin to get +1/+1.
- 8 November 2024You must choose an existing creature type, such as Human or Warrior. Card types such as artifact and supertypes such as legendary can't be chosen.