A loc kit — localization kit — is the complete package of materials a developer provides to their localization partner at project start. The quality and completeness of the loc kit directly determines how quickly and accurately localization can begin. A complete loc kit allows the localization team to start translation immediately; an incomplete loc kit triggers delay loops as the provider requests missing elements. This guide explains what every loc kit should include, why each element matters, and what happens when elements are missing.

The Core Loc Kit Elements

A complete game localization kit contains: (1) String files in an exportable format — the actual text of all game strings in a format the CAT tool can import (XLIFF, JSON, CSV, PO, YAML, or engine-native export). String files must include string IDs/keys, source text, and ideally context notes. (2) A reference build — a playable version of the game (build, executable, or video walkthrough) that allows translators and LQA testers to see strings in context. (3) A project glossary — a list of game-specific terms that must be translated consistently: character names, faction names, ability names, game system terms, and any UI label that appears frequently. (4) Character notes (for dialogue-heavy games) — personality descriptions, speech register (formal/casual, young/old, villain/hero), and key character relationships for the game’s main characters. (5) Context notes — any text-level context notes for individual strings where the context isn’t obvious from the string itself.

String File Formats

String files must be in a format that a CAT tool can parse and that preserves string IDs alongside string content. The best formats for game localization: XLIFF 1.2 or 2.0 — the industry-standard XML localization format, supported by all major CAT tools; JSON — common in web-based games and Unity projects (flat key-value JSON is easily parseable; nested JSON is also supported by most tools); CSV — simple comma-separated format with key and value columns; PO files — standard for open-source and Linux software localization, well-supported; YAML — used in some game frameworks. Unity and Unreal have native export tools that produce XLIFF or CSV. The key requirement is that string IDs (keys) are preserved in the export — translators need to be able to return translated strings to the correct string slot in the game.

Why the Reference Build Matters

The reference build — a playable version of the game — is not optional in a professional loc kit. Translators need the reference build to: understand context (is this label a button, a menu header, or a tooltip?); see how strings are used in gameplay (what does the ability actually do, so the description is accurate?); identify character personality from in-game presentation; and check that translations feel appropriate for the game’s tone and visual style. LQA testers need the reference build to verify that translated text fits in UI containers, that fonts render all target language characters, and that strings appear in the correct in-game context. Without a reference build, translators work blind and LQA is impossible. A video walkthrough is a partial substitute for limited-access situations, but a build is always preferred.

Glossary Preparation

The project glossary is the single highest-leverage document in a loc kit. A good glossary: lists all game-specific terms that must be translated consistently; provides the source language term and, where available, an approved target language term or translation guidance; explains the context for ambiguous terms (what ‘spirit’ means in the game — is it the player’s energy resource or a type of supernatural being?); flags terms that should NOT be translated (character names to keep as-is, trademark terms). A glossary built before translation begins prevents the most common game localization quality complaint: inconsistent terminology — where the same concept is translated three different ways across different files. A glossary delivered mid-translation requires a consistency correction pass to update already-translated strings.

Frequently Asked Questions