Language is fluency and comprehension in one particular tongue; each language is a separate skill with its own Mastery Level.
Complexity. Every native speaker is technically fluent, so Mastery Level does not measure whether a character can speak but how far they can go — what ideas they can express and follow, in their own tongue as much as a foreign one. When two people converse, the lesser of their two Indexes sets the ceiling:
| Index | Complexity | What it supports |
|---|---|---|
| 0–2 | Limited | Simple questions and answers; narrow vocabulary; halting or ungrammatical speech. |
| 3–5 | Basic | Routine social exchange; unspecialised vocabulary. The average native speaker. |
| 6–7 | Advanced | Intricate social exchange; specialised vocabulary. The educated and the well-born. |
| 8+ | Profound | Erudite, detailed, and equal to any concept. The scholar, the jurist, the herald. |
That ceiling limits persuasion as much as conversation. A character with Limited fluency may still lie, but only in short, plain sentences — and being reduced to short, plain sentences is itself conspicuous.
Mutual intelligibility. Some languages are close enough that a speaker of one can make headway in the other, and related tongues should be treated as partially available rather than closed.
Accent. How foreign a character sounds is the product of their Eloquence Index × Language Index:
| Total | Accent |
|---|---|
| 01–19 | Heavy |
| 20–29 | Noticeable |
| 30–39 | Slight |
| 40+ | None |
Because it is a product, neither factor saves the other: a naturally eloquent speaker with a weak grasp of the language is still obviously foreign, and years of study will move an accent from heavy to slight without ever quite erasing it.
Reading requires a Script skill as well as this one — see Script for the reading and scribing tests, in which Language supplies the comprehension half.