AI story series bible: the one-page template we fill in before episode two

Episode one is easy. Episode two is where series break.

The first episode of an AI story always looks fine, because everything in it was decided on the same afternoon. Episode two is made a week later, from memory. The jacket is a slightly different red. The voice is described in different words. The reference images are attached in a different order. By episode five the character is a cousin of the one people subscribed for.

Every guide to AI series says you need a series bible, and they are right. The common version is a page with a premise, a cast list, the tone and some style words. That is a writing document. What it leaves out is everything the engine actually reads: which images, in which order, which exact sentence describes the character, which voice line, which engine for which kind of shot, and what an episode costs. Those are the things that drift, so those are the things our bible pins down.

Here is the template we fill in, field by field, and why each field is there.

The template

section	what goes in it	why it is there
1. premise	two sentences: who, what they want, what is in the way	so every episode is about the same thing
2. episode formula	length, number of shots, where the hook and the cliffhanger sit	so episodes feel like one series
3. cast sheets	one reference sheet per recurring character, with file names	the images the engine holds identity from
4. descriptor blocks	one fixed paragraph per character, pasted unchanged	the words the engine reads every time
5. voice lines	one fixed voice description or cloned voice per character	so the voice does not age or change accent
6. reference order	the exact order references are attached, per engine	so @Image1 is the same character in every shot
7. engine rules	which engine for dialogue, action, establishing shots	so look and cost stay steady
8. style words	the exact style phrase, never reworded	so episode six looks like episode one
9. always and never	short lists of things that must or must not appear	to stop drift you already caught once
10. continuity log	one row per episode: what changed and why	so changes are on purpose
11. credit line	what one episode costs, and the one-time setup	so the series fits the budget

Sections 1 and 2: premise and formula

Keep the premise to two sentences. If you cannot say it in two, the episodes will wander. The formula is the shape every episode follows. Ours for a 45-second episode is usually: a 4-second hook, five or six story shots, a 4-second cliffhanger. Writing it down stops episode seven from being 90 seconds because the idea was good.

Section 3: the cast sheets

One reference sheet per recurring character: front, three-quarter left, three-quarter right, full body. Store the file names in the bible, not just the images, so you always attach the same files. A sheet in our studio is 30 credits, made once. The character reference sheet guide shows what each angle is for.

Section 4: the descriptor block

This is the paragraph about the character that goes into every prompt, word for word. Hair, face, build, outfit, one or two defining details. "Yellow raincoat, red zip, hood down" means the same thing to the engine every time. "Rain jacket" in episode four means a different jacket. Copy and paste it; never retype it. Our descriptor block guide has the fields we use.

Section 5: the voice line

Voice drift is the one people notice last and viewers notice first. Pick one of two routes and write it in the bible:

• A fixed voice description, one sentence, pasted unchanged into every voiced prompt: age, pitch, pace, accent, one quality.
• A cloned voice stored on the character. In our studio, cloning your own voice onto a character is 50 credits once, and the voice is then reused on every render.

Either way, also write a pronunciation line for any name the engine might stumble on.

Section 6: the reference order

This is the field almost nobody writes down, and on some engines it decides who is who. On Seedance, reference images are addressed by their position in the list: @Image1 is whatever you attached first. If the hero is attached first in episode one and second in episode two, @Image1 now points at someone else. Kling O3 Pro addresses saved characters as @Element1, @Element2, and Veo 3.1 Fast simply calls them image 1, image 2.

So the bible lists the order, per engine, and the order never changes:

engine	slot 1	slot 2	slot 3 onward
Kling O3 Pro, up to 5 elements	hero	second lead	recurring prop or location
Seedance 2.5, up to 30 images	hero, all angles	second lead, all angles	location frames
Seedance 2.0, up to 9 images	hero, 4 images	second lead, 4 images	1 location frame
Veo 3.1 Fast, up to 3 images	hero	hero or second lead	nothing spare

These caps are the ones our studio enforces per render. A shot that names more characters than the engine takes is refused before it bills.

Section 7: engine rules

Write down which engine handles which kind of shot. Ours, for most series:

• Dialogue: Kling O3 Pro, 30 credits a voiced second, up to 15 seconds per shot.
• Big motion or busy scenes: Seedance 2.5, up to 30 reference images, 70 credits a second at 720p.
• Short single-character beats: Veo 3.1 Fast, 30 credits a voiced second, always 8 seconds with a reference.

Switching engines mid-series changes the look slightly. That is fine if it is a rule; it is drift if it is a mood.

Sections 8 to 10: style, always and never, continuity

The style phrase is one line, for example "3D animated, soft studio lighting, warm palette". Never reword it. The always and never lists are short and grow when something goes wrong: "always: scar over left eyebrow", "never: hood up indoors". The continuity log is one row per episode: episode number, character, what visibly changed, why. A haircut after a time skip is a story choice. A haircut nobody wrote down is drift.

Section 11: the credit line

This is what a series bible on the first page of Google never includes, and it decides whether the series survives month two. Here is ours for a 45-second episode with two characters on Kling O3 Pro at 720p:

item	credits
37 seconds voiced at 30 a second	1,110
two 4-second silent shots at 24 a second	192
three writer runs: draft, tighten, next part	15
one export	20, free from Creator up
captions, one started minute	8, free from Creator up
one retake of an 8-second voiced shot	240
per episode	1,585

One-time setup, outside the per-episode line: two character sheets at 30 credits each and one voice clone at 50, so 110 credits. At the Lite rate of 1,000 credits for $10, an episode like this is about $15.85 with the retake allowance and about $13.45 without it.

Write your own version of this table into the bible, and when an episode goes over, note why in the continuity log. Our episode cadence guide covers how often to post once the budget is set.

Keep it to one page

A bible nobody opens is no better than none. Ours fits on one page, lives next to the project, and gets opened before every episode. In our studio most of it lives on the character itself: the sheet, the voice and the saved references travel with the character into every part, and Part 2 starts from Part 1's cast rather than from a blank prompt. The rest, the formula, the style words and the log, is a page you keep yourself.

FAQ

What is a series bible for AI video?

It is a one-page document that fixes everything an AI series must repeat: premise, episode formula, character sheets, the exact character description, voice, reference order, engine rules, style words and a per-episode cost. ReelDouble stores the sheet and voice on the character so every part reuses them.

What should an AI animated series bible include?

Premise, episode formula, a reference sheet and fixed descriptor paragraph per character, a voice line, the order references are attached, which engine handles which shot, the exact style phrase, always and never lists, a continuity log and a per-episode credit budget.

Why does reference image order matter in AI video?

On Seedance the prompt calls images by position, so @Image1 is whichever image was attached first. Change the order between episodes and the prompt points at a different character. On ReelDouble, Kling O3 Pro uses @Element1 and Veo 3.1 Fast uses plain image numbers.

How much does one AI series episode cost?

On ReelDouble a 45-second, two-character episode on Kling O3 Pro at 720p is about 1,345 credits including writing, export and captions, or 1,585 with one retake. Setup is 110 credits once for two sheets and a voice clone.

How do I keep my AI character's voice the same every episode?

Paste one fixed voice description unchanged into every voiced prompt, or clone a voice onto the character once. On ReelDouble a clone of your own voice is 50 credits and is reused on every render after.