Smart Collections

A smart collection is a collection defined by filter criteria, not by hand-picking. You set filters ("SNES games tagged RPG", "Zelda franchise", "playable in the browser") and RomM keeps the list in sync as you add ROMs and edit metadata.

For hand-curated collections, see Collections, and for auto-generated groupings, see Virtual Collections.

How filters work

A smart collection holds a fixed set of filter fields (it isn't a generic rule engine). Each field accepts one or more values, and multi-value fields take a <field>_logic companion that picks any (OR) or all (AND) within that field. Different fields are always combined with AND.

That has two big consequences:

No top-level OR. You can't express "Franchise = Zelda OR Title contains 'zelda'". Different fields always AND.
No negation. Filters are inclusion-only. There's no "Status is not Complete" or "exclude Genre RPG". Pick the values you want, not the ones you don't.
No nesting. A smart collection can't filter on another smart collection.

Supported fields

Multi-value

Each takes one or more values. All (except platform_ids) also accept a <field>_logic companion of any (OR, the default) or all (AND).

Field	Matches
`platform_ids`	One or more platforms
`genres`	Game genres
`franchises`	Franchises
`collections`	Membership in named collections
`companies`	The combined company credit
`publishers`	Publishers specifically
`developers`	Developers specifically
`age_ratings`	ESRB / PEGI categorical labels
`regions`	Region tags
`languages`	Language tags
`tags`	Arbitrary filename tags
`statuses`	Your play status (backlogged, playing, etc.)
`player_counts`	Supported player counts
`metadata_providers`	Which provider matched the game

Boolean

Field	Matches
`matched`	Games a metadata provider matched
`verified`	Games with a verified match
`favorite`	Your favourites
`duplicate`	Games with more than one version
`playable`	Platforms with a browser player
`has_ra`	Games with a RetroAchievements set
`has_saves`	Games you have a save for
`has_states`	Games you have a state for
`has_soundtrack`	Games with tracks in the Jukebox
`missing`	Games flagged missing from the filesystem
`physical`	Physical games, entries with no file on disk

Single-value

Field	Matches
`search_term`	Case-insensitive substring match against the title
`collection_id`, `virtual_collection_id`	Membership in one specific collection
`hltb_main_story_min`, `hltb_main_story_max`	A game length range

Game length

Lengths come from HowLongToBeat, so you need HLTB_API_ENABLED=true and a scan that matched the game. It's main story time, and you can set a floor, a ceiling, or both. The gallery sorts and filters by it too, without needing a collection. Games HowLongToBeat never matched have no length at all and drop out of a length filter entirely.

Examples

"SNES RPGs I'm playing or haven't started"

Platform: snes
Genre: RPG
Status: Never Played, Playing

Inclusion-only, so list the statuses you want and let everything else fall away.

"Arcade games playable in browser"

Platform: arcade
Playable in browser: yes

"Short games I own physically and haven't started"

Physical: yes
Status: Never Played
Main story: up to 8 hours

"Zelda franchise"

Franchise: The Legend of Zelda

To match by title substring instead, use Title: zelda. You can't OR the two together in one collection (different fields always AND).

Public / private

Same visibility model as standard collections:

Private: only you see it. Personal-data fields (Status) only make sense here.
Public: everyone on the instance sees it. Your personal-data filters still apply, so a public smart collection filtering on Status will reflect your statuses for every viewer.

Refresh behaviour

Smart collections refresh on add/remove/edit of ROMs, and on scan. No manual refresh needed!