Collected Company

In Commander, Collected Company is a role-player rather than a staple — the 99-card singleton structure means you'll whiff more often than in a constructed deck, and it only hits creatures with mana value 3 or less, which cuts out a lot of what Commander decks want to do. It earns its slot in go-wide creature builds that deliberately pack cheap creatures: Elf tribal, Human tribal, and combo decks that assemble a two-piece engine from small creatures are where it consistently delivers. In Modern and Pioneer, Collected Company is a format-defining card in creature-combo shells — Elves, Devoted Druid combo, and Humans have all used it as a primary engine. Legacy treats it as a fringe option; the competition for three-mana instants is fierce and tutors are more reliable. Vintage has the same issue at higher power density, so it rarely sees play.