Keyword: Metalcraft

Metalcraft — Chrome Steed gets +2/+2 as long as you control three or more artifacts.

Target player sacrifices an attacking creature.
Metalcraft — That player sacrifices two attacking creatures instead if you control three or more artifacts.

Metalcraft — : Tap target artifact, creature, or land. Activate this ability only if you control three or more artifacts.

Each player shuffles the cards from their hand into their library, then draws that many cards.
Metalcraft — If you control three or more artifacts, Molten Psyche deals damage to each opponent equal to the number of cards that player has drawn this turn.

Metalcraft — Rusted Relic is a 5/5 Golem artifact creature as long as you control three or more artifacts.