Loose is where most people start and where the hobby stays honest. A bare cartridge or disc, no box, no manual — the object stripped to the thing you actually play. Supply is deepest here and prices lowest, which makes loose the collector's classroom: it is where you can afford to learn the variants, the labels, and the authenticity tells before you spend real money a tier up.
Loose demand comes from people who want to play, so it tracks the game's enduring appeal more than its scarcity story. A beloved, common title has a healthy loose market; an obscure, scarce title may have a thin one despite a hot sealed market. This is the clearest demonstration of the three-tier model's independence — loose and sealed can point in opposite directions on the same title.
'Loose' does not mean 'undifferentiated'. Cartridge labels were revised across a title's life — colour shifts, layout changes, 'Player's Choice' and equivalent reprint markings — and the board inside can carry ROM revisions that collectors track. On a handful of titles a specific early label or board revision commands a real premium even loose. The eye you build here transfers directly upward: the same variant literacy governs the CIB and sealed tiers.
Bare media is the easiest thing to fake, because there is no box or seal to forge — just a cartridge shell or a disc. Reproduction cartridges, reprinted labels, and burned discs are common at the loose tier, especially for scarce or expensive titles. The defences are physical: correct shell characteristics, period-correct label printing and materials, the right board and chips inside, and — for discs — correct pressing and matrix details. When a loose copy of a normally-expensive title is suspiciously cheap, assume reproduction until the physical evidence says otherwise.
The disciplined path is to build loose first: acquire the run cheaply and authentically, learn the labels and boards and authenticity tells hands-on, and only then move up to CIB and sealed with an eye you have actually trained. Loose is not the lesser tier — it is the one that teaches you how to collect the other two.