GPT-6 Luna - NC Bench

openai/gpt-6-luna

GPT-6 Luna

via OpenRouter

Release Date

Sep 22nd, 2026

Context Size

Reasoning

Benchmark Cost

$0.28

Speed

58.6 tok/s

Subcategories

Bad Writing Habits

Detects common prose quality anti-patterns in AI-generated creative writing, including passive voice, past progressive overuse, weak dialogue tags, filter words, purple prose, cliches, AI-ism words/adverbs/names, and more.

Scenario	#1	#2	#3	#4	#5	Total
Detailed Writing Rules
Fantasy: entering an ancient ruin Creative Writing Hallucination	89	88	88	87	85	87%
Horror: alone in an eerie place at night Creative Writing Hallucination	92	91	89	88	86	89%
Literary fiction: old friends reunite Creative Writing Hallucination	91	89	89	88	86	89%
Mystery: examining a crime scene Creative Writing Hallucination	89	88	88	86	85	87%
Romance: separated couple reunites Creative Writing Hallucination	90	88	87	86	85	87%
Thriller: chase through city streets Creative Writing Hallucination	91	90	90	89	88	90%
Detailed Writing Rules						88.26%
genre
Fantasy: entering an ancient ruin Creative Writing Hallucination	92	89	89	88	84	88%
Horror: alone in an eerie place at night Creative Writing Hallucination	90	89	88	87	87	88%
Literary fiction: old friends reunite Creative Writing Hallucination	91	90	90	88	88	89%
Mystery: examining a crime scene Creative Writing Hallucination	91	89	88	88	88	89%
Romance: separated couple reunites Creative Writing Hallucination	93	91	89	88	87	90%
Thriller: chase through city streets Creative Writing Hallucination	93	93	90	89	88	91%
genre						89.16%
Novelcrafter Default Prompt
Fantasy: entering an ancient ruin Creative Writing Hallucination	89	88	88	88	88	88%
Horror: alone in an eerie place at night Creative Writing Hallucination	90	89	88	87	86	88%
Literary fiction: old friends reunite Creative Writing Hallucination	89	88	87	86	86	87%
Mystery: examining a crime scene Creative Writing Hallucination	90	88	87	87	85	87%
Romance: separated couple reunites Creative Writing Hallucination	88	88	87	86	84	87%
Thriller: chase through city streets Creative Writing Hallucination	89	88	87	87	86	87%
Novelcrafter Default Prompt						87.45%
88.29%

Codex Extraction

Evaluates a model's ability to extract structured codex entries (characters, locations, objects, lore) from prose passages and return them as well-formed XML.

Scenario	#1	#2	#3	#4	#5	Total
Long: The Spire of Echoes (Dense) Tooling Reasoning	96	95	95	95	93	95%
Medium: The Hollow (Inferred) Tooling Reasoning	97	97	96	96	94	96%
Medium: Through the Thornveil (Scattered) Tooling Reasoning	96	94	93	91	91	93%
Short: The Rusty Lantern (Explicit) Tooling Reasoning	94	93	93	93	89	92%
94.06%

Codex Red Herring (False Positive Detection)

Tests whether models correctly report "no violations" when a codex is fully consistent with the prose passage. Models that hallucinate false violations (false positives) fail. Uses a 2×2 matrix of text length × codex size, with bare and detailed-entry variants.

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
basic entries
Long text (~1594 words), big codex (51 entries) Hallucination	25	25	25	25	25	25	25	25	8	5	21%
Long text (~1594 words), small codex (11 entries) Hallucination	100	100	100	100	100	100	100	100	100	100	100%
Short text (~524 words), big codex (51 entries) Hallucination	100	100	100	100	100	100	100	25	25	25	78%
Short text (~524 words), small codex (11 entries) Hallucination	100	100	100	100	100	100	100	100	100	100	100%
basic entries											74.70%
detailed entries
Long text (~1594 words), big codex (51 detailed entries) Hallucination	100	100	30	17	13	8	7	6	5	4	29%
Long text (~1594 words), small codex (11 detailed entries) Hallucination	100	100	100	100	100	100	100	100	100	100	100%
Short text (~524 words), big codex (51 detailed entries) Hallucination	100	100	100	50	42	25	25	25	25	10	50%
Short text (~524 words), small codex (11 detailed entries) Hallucination	100	100	100	100	100	100	100	100	25	25	85%
detailed entries											66.04%
70.37%

Codex Violation Detection

Detects factual inconsistencies between a story bible and prose passages. The model must output structured XML identifying each violation with paragraph number and substring.

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
matrix
Large codex (40 entries), long passage (1,019 words) Tooling Reasoning	90	86	86	85	85	84	84	79	77	76	83%
Large codex (40 entries), short passage (165 words) Tooling Reasoning	98	97	96	94	93	93	92	89	89	87	93%
Small codex (7 entries), long passage (734 words) Tooling Reasoning	92	88	88	87	83	83	83	83	80	80	85%
Small codex (7 entries), short passage (165 words) Tooling Reasoning	100	100	100	100	100	100	100	100	100	100	100%
matrix											90.16%
tiers
5 codex entries Tooling Reasoning	100	100	100	100	100	100	100	100	100	100	100%
10 codex entries Tooling Reasoning	100	100	100	100	100	92	86	86	86	74	92%
20 codex entries Tooling Reasoning	100	100	100	92	89	89	89	85	85	85	91%
40 codex entries Tooling Reasoning	100	100	100	100	100	99	95	95	95	95	98%
tiers											95.48%
92.82%

Data extraction

Extract key details from a given block of text.

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
All valid emails Utility	100	100	100	100	100	100	100	100	100	100	100%
Contextual pronoun Utility	100	100	100	100	100	100	100	100	100	100	100%
Fruits excluding citrus Utility	100	100	100	100	100	100	100	100	100	100	100%
Future event time Reasoning	100	100	100	100	100	100	100	100	100	100	100%
Guess the pet Reasoning	100	100	100	100	100	100	100	100	100	100	100%
Highest-rated movie Reasoning	100	100	100	100	100	100	100	100	100	100	100%
Indirect birth year Reasoning	100	100	100	100	100	100	100	100	100	100	100%
What instrument does Lucy play? Reasoning	100	100	100	100	100	100	100	100	100	100	100%
What's the color of the car? Utility	100	100	100	100	100	100	100	100	100	100	100%
Who's the sister? Reasoning	100	100	100	100	100	100	100	100	100	100	100%
Who's the tallest? Reasoning	100	100	100	100	100	100	100	100	100	100	100%
100.00%

Dialogue tags

Various tasks related to dialogue tags in text.

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
dialogue-200
Write 200 words with 10% dialogue Rule Following Utility	50	50	50	50	50	49	25	20	2	1	35%
Write 200 words with 50% dialogue Rule Following Utility	50	49	45	42	27	18	14	1	0	0	25%
Write 200 words with 90% dialogue Rule Following Utility	67	56	50	50	50	43	23	18	6	3	37%
dialogue-200											32.01%
dialogue-500
Write 500 words with 30% dialogue Rule Following Utility	9	2	1	1	0	0	0	0	0	0	1%
Write 500 words with 50% dialogue Rule Following Utility	50	50	26	19	17	14	11	4	3	0	19%
Write 500 words with 70% dialogue Rule Following Utility	79	49	49	16	13	11	3	2	0	0	22%
dialogue-500											14.33%
Ungrouped
Write unattributed dialogue Rule Following	100	100	100	100	100	61	61	61	61	1	74%
30.48%

Language Comprehension

Does the model understand more than just English?

Scenario	#1	#2	#3	#4	#5	Total
Asking for directions (Dutch) Language	100	100	100	100	0	80%
Asking for directions (German) Language	100	100	100	100	0	80%
Friend got new kittens (German) Language	100	100	100	100	100	100%
Friend got new kittens (Tagalog) Language	100	100	100	100	100	100%
90.00%

Language Writing

Can the model generate text in different languages?

Scenario	#1	#2	#3	#4	#5	Total
Character dialogue (French) in a story Language	100	100	100	100	100	100%
Character dialogue (German) in a story Language	100	100	100	96	91	97%
Character dialogue (Hindi) in a story Language	100	100	100	100	100	100%
Character dialogue (Italian) in a story Language	100	98	97	59	48	80%
Character dialogue (Spanish) in a story Language	100	100	100	94	92	97%
94.99%

N-Length Sentences

Write sentences with exactly N words

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
Write sentences with 5 words each Utility	100	98	98	96	94	93	87	81	81	79	91%
Write sentences with 10 words each Utility	100	95	93	91	90	84	84	79	75	72	86%
Write sentences with 20 words each Utility	100	92	67	59	50	50	31	18	15	0	48%
75.00%

Novel outline

Handle questions about the outline of a novel in various formats

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
outline-count
Count acts Utility	100	100	100	100	100	100	100	100	100	100	100%
Count chapters Utility	100	100	100	100	100	100	100	100	100	100	100%
Count scenes Utility	0	0	0	0	0	0	0	0	0	0	0%
outline-count											66.67%
pov-count
Count point of views for Jack and Olivia Utility	0	0	0	0	0	0	0	0	0	0	0%
Count point of views for Jack Harper Utility	0	0	0	0	0	0	0	0	0	0	0%
Count point of views for Olivia Utility	0	0	0	0	0	0	0	0	0	0	0%
pov-count											0.00%
33.33%

Relationship tree

Extracts a deterministic XML family and relationship tree from cumulative literary prose.

Scenario	#1	#2	#3	#4	#5	Total
Core relationship tree Tooling Reasoning Hallucination	84	70	66	60	60	68%
Family relationship tree Tooling Reasoning Hallucination	80	78	77	74	73	77%
72.44%

Text Replacement

Tests deterministic text transformations: renaming characters/locations, expanding contractions, tense rewriting, POV shifts, gender swaps, combined transformations, and word avoidance. Scored by checking each expected change independently.

Scenario	#1	#2	#3	#4	#5	#6	#7	Total
Generic Prompt
Avoid said/asked/replied/answered Text Editing	100	100	100	100	100	100	100	100%
Character rename: Elena->Mirabel, Gregor->Aldric Text Editing	100	100	100	100	100	100	100	100%
Combined: 3rd person past → 1st person present Text Editing	99	98	98	98	95	95	89	96%
Expand all contractions Text Editing	92	92	91	91	91	91	91	91%
Location rename: market square, outer ring, bridge, northern mines Text Editing	100	100	100	100	100	100	100	100%
Multi-character gender swap: Priya(F)->Rohan(M), Mara unchanged Text Editing	100	100	100	100	100	100	100	100%
Passive voice → active voice Text Editing Hallucination	99	98	98	98	98	98	95	98%
POV shift: 3rd person to 1st person (Elena's perspective) Text Editing	100	100	100	100	100	100	100	100%
Tense rewriting: past to present Text Editing	93	93	89	89	89	89	87	90%
Generic Prompt								97.26%
Specific Prompt
Avoid said/asked/replied/answered Text Editing	100	100	100	100	100	100	100	100%
Character rename: Elena->Mirabel, Gregor->Aldric Text Editing	100	100	100	100	100	100	100	100%
Combined: 3rd person past → 1st person present Text Editing	100	100	100	100	100	99	99	100%
Expand all contractions Text Editing	100	100	100	100	100	100	99	100%
Location rename: market square, outer ring, bridge, northern mines Text Editing	100	100	100	100	100	100	100	100%
Multi-character gender swap: Priya(F)->Rohan(M), Mara unchanged Text Editing	100	100	99	99	99	99	97	99%
Passive voice → active voice Text Editing Hallucination	98	98	98	97	96	96	95	97%
POV shift: 3rd person to 1st person (Elena's perspective) Text Editing	100	100	100	100	100	100	100	100%
Tense rewriting: past to present Text Editing	100	100	100	100	100	100	100	100%
Specific Prompt								99.51%
98.39%

Tool usage within Novelcrafter

Output messages that are related to tool usage within Novelcrafter

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
Create alternate prose sections Tooling	100	100	100	100	100	100	100	100	100	100	100%
100.00%

Voice/dialogue sheets

Extract dialogue from given text as voice sheets.

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
Multiple speakers Rule Following	100	0	0	0	0	0	0	0	0	0	10%
Simple Rule Following	100	100	0	0	0	0	0	0	0	0	20%
Simple (1-shot) 1-shot Rule Following	100	100	100	100	100	100	100	0	0	0	70%
Simple (5-shot) Few-shot Rule Following	100	100	100	100	100	100	100	100	100	100	100%
Unattributed dialogue Rule Following	0	0	0	0	0	0	0	0	0	0	0%
40.00%

Write N of X

Write exactly N words/sentences/paragraphs...

Scenario	#1	#2	#3	#4	#5	#6	#7	#8	#9	#10	Total
paragraphs
1 paragraph summary Utility	100	100	100	100	100	100	100	100	100	100	100%
3 paragraph summary Utility	100	100	100	100	100	100	100	100	100	100	100%
5 paragraph summary Utility	100	100	100	100	100	100	100	100	100	100	100%
paragraphs											100.00%
sentences
1 sentence summary Utility	100	100	100	100	100	100	100	100	100	100	100%
3 sentence summary Utility	100	100	100	100	100	100	100	100	100	100	100%
10 sentence summary Utility	100	100	100	100	100	100	100	100	100	100	100%
20 sentence summary Utility	100	100	100	100	100	100	100	100	98	2	90%
50 sentence summary Utility	100	100	100	98	77	0	0	0	0	0	48%
sentences											87.51%
words
10 word summary Utility	98	77	77	77	77	54	54	54	54	27	65%
20 word summary Utility	98	98	92	92	92	77	77	77	54	27	79%
50 word summary Utility	77	54	2	0	0	0	0	0	0	0	13%
100 word summary Utility	9	9	2	2	0	0	0	0	0	0	2%
200 word summary Utility	0	0	0	0	0	0	0	0	0	0	0%
words											31.81%
68.97%