Glossary

Glossary

Use this page when a word interrupts your reading. Code identifiers keep their exact spelling; these definitions explain the idea around them. For a worked example, see Modding Basics.

Files and tools

Word	Meaning here
Mod	An add-on folder that changes some game behavior or content.
ROM	A file containing cartridge game data, supplied by the player for import.
Import	Read a supported file and prepare local data the app can use.
Cache	Generated local files reused on later launches. It is not your mod source.
Asset	A picture, sound, font, or other media file used by the game.
Asset transform	Instructions that create changed art locally from the player's imported data.
Manifest	The manifest.json file describing a mod and its requirements.
Source checkout / repository	A local copy of the project's source files. The engine and wiki are separate repositories.
Root folder	The top folder of the particular project being discussed. “Engine root” contains src/ and tools/.
Relative path	A location measured from a stated folder, such as assets/front.png inside a mod.
Terminal / shell	A text interface for running commands. Run commands from the stated folder.
CLI	Command-line interface: a tool you use by typing commands.
Scaffold	Create a starting folder and files automatically.
Modkit	The engine's mod-author tool, tools/modkit.py.
Cartkit	The engine's tool for authoring custom carts.
Headless	Running checks without opening the normal game window.
Fixture	Small test data supplied with the project; it does not contain every real game ID.
Validate	Check specified file/data rules. A pass is not proof of every gameplay outcome.

Code and game data

Word	Meaning here
Lua	The programming language used by the engine and mod entry files.
JSON	A format for information such as the manifest; its punctuation differs from Lua.
API	The operations and data the engine exposes for mod authors to use.
Value	A piece of information, such as a number, text, or a table.
String	Text inside quotes.
Boolean	true or false.
nil	Lua's absence of a value.
Variable	A name your code uses to refer to a value.
Table	Lua's container for named fields or a list of entries.
Array / list	Ordered entries, usually numbered starting at 1 in Lua.
Field / key	The name of a value inside a table; speed is a field in baseStats.
ID	An internal identifier, such as GROWLITHE. It can differ from the displayed name.
Record	Data describing one thing, such as a move or creature.
Registry	A named collection of game records or configuration, such as pokemon or moves.
Schema	Rules describing which fields and value types a record accepts.
Required / optional	A required value must be supplied; an optional value may be omitted according to its contract.
Register	Add a record. Existing IDs can collide; use the registry's documented rules.
Patch	Change selected values while keeping the others, following that registry's merge rules.
Override	Replace a record or contribution; not the usual choice for a one-field tweak.
Merge	Combine the base data and mod contributions. Lists and named fields can combine differently.
Compose	Collect multiple contributions. It does not mean every subfield combines: one winning NPC talk script is chosen per text ID.
camelCase	Word style such as baseStats, used by many record fields.
snake_case	Word style such as map_scripts; copy API names exactly.
Function	Instructions that can be called with inputs and can return results.
Argument / parameter	A value supplied to a function / the name that receives it.
Return value	The result a function gives its caller. Some functions return several values.
Callback / handler	A function another part of the game calls when needed.
Context / ctx	A table carrying the information and tools for one operation. Its fields depend on the API.
Event / listener	A notification that something happened / a callback subscribed to it.
Payload	The information carried by an event, usually in a table.
Hook / wrapper	An extension point in a decision / a function participating at that point.
next in a hook	The next function in that hook's chain. Follow the individual hook's call and return rules.
Middleware	A chain of functions processing an operation; see Events and Hooks.
Facade	A supported interface that hides differences in underlying engine objects.
Adapter	Code translating between interfaces or versions.
Serialization	Turning live data into a storable format; restoring it is deserialization.

Timing, saves, and compatibility

Word	Meaning here
Vanilla	The game's behavior without active mod changes.
Lifecycle	The stages of loading, running, and saving.
Entry function	The function returned by a mod's main.lua, called during mod loading.
Runtime / live game	The running game after startup, when a world/save can be available.
Freeze	The point after which content registrations cannot be changed until a reload.
Namespace	A separate area of names or data; mod.save is separated by mod ID.
State	Information about the current situation, such as quest progress.
Profile	A named set of mod enablement/settings choices.
Save slot	A separately selectable playthrough/save.
Migration	Code that updates old saved data to a newer expected format.
Quarantine	Keeping incompatible saved content aside according to the save model, instead of treating it as valid current content.
Checkpoint	In a tutorial, an observable test. In mod.checkpoints, an engine snapshot facility; these are different uses of the word.
Dependency	Another mod a mod needs.
Version / semver	A release number / rules for comparing numbers such as 1.2.0.
Compatibility	Whether particular versions or data can work together. Check the feature's actual requirements.
Fingerprint / digest / hash	A compact computed summary used to compare content. Matching values do not override the current link-play rules.
Pin	A custom cart's declaration of a particular mod/release choice.
Seal	A custom cart's restriction on changing its declared configuration; see Custom Carts.
Tri-ledger	The base game's three records of matched behavior, known differences, and new features, described in Compatibility. You do not need this term for your first mod.
Parity / parity oracle	Matching original game behavior / the reference used to judge that match.
No-op	An operation that does nothing in that situation.
Sandbox / isolated callback	Restrictions around mod code / a callback whose errors are caught at a defined boundary. Neither phrase is a promise that every possible failure is harmless.

Link play is set up in the launcher, using a vanilla cart or a sealed custom cart. Mods can run as part of that sealed cart; freely enabled mods are not the supported link path. A compatibility field or a cosmetic-only change does not bypass that requirement. Follow Link Play.

Game and media shorthand

Word	Meaning here
Gen 1 / Gen 2	The first/second generation of Pokemon games. This wiki's introductory examples target Red.
NPC	Non-player character: a person in the game controlled by the game.
Sprite	A game image for a character or creature.
Palette	A selected set of colors used to draw an image.
Tile / block / cell	Different map units. See the diagram in Tutorial 07 before choosing coordinates.
HUD	Heads-up display: information drawn over gameplay, such as HP/status.
SFX	Sound effects, such as a save sound.
Chiptune / ChipAsm	Music built from sound-chip-style instructions / the engine's authoring helper for those instructions.
Channel	One sound voice in a chip program, or one audio channel in a file; check the context.
DV	Determinant value: an original-game value involved in a creature's stats.
QoL	Quality of life: a convenience feature such as easier menu navigation.
SGB / GBC	Super Game Boy / Game Boy Color.

Missing a word? The precise type and behavior belong in the linked API reference. Use this page for the short explanation, not as a replacement for a function's contract.