Prompting Guide

Lucy 2.5 transforms video from a simple written prompt. Strong prompts describe the visible edit you want: what should be added, replaced, removed, restyled, transformed, animated, or preserved. Think of the prompt as short creative direction. You do not need technical language. You do need clear visual details. Lucy 2.5 can also make effects feel physically present. For more grounded results, describe how an edit interacts with the subject, their motion, and the environment: light reflects on skin, smoke wraps around shoulders, particles bounce off surfaces, and clothing moves with the body.

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Core prompting principles

Strong prompts answer five questions:

• What should change? Name the person, object, garment, background, material, or effect.
• What should it become? Describe the new visual result.
• Where should it apply? Anchor the edit to a body part, object, garment, surface, or background.
• How should it interact? For physical effects, describe how it attaches, follows, wraps, reflects, casts light, or responds to motion.
• What should stay the same? Preserve the person’s identity, face, hair, pose, camera angle, motion, room, or background when needed.

Keep prompts clear and compact. A useful target is 2–4 concise sentences, not a long paragraph. Use visible identifiers instead of frame position. If several similar objects appear, identify the target by color, material, pattern, text, logo, shape, or another visible detail.

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Use reference images intentionally

Reference images work better when the prompt says which part of the image matters and how to apply it. Treat the reference image as visual material, and the prompt as the instruction. A reference image can supply a specific item to add to the video, or an overall art style for the whole video. Good reference images usually:

• Show the item clearly
• Avoid extra people when possible
• Avoid cluttered backgrounds
• Show the full shape of the garment, product, character, or object
• Avoid folded, hidden, or partially blocked items

Do not rely on an empty prompt. Even with a strong reference image, a bit more instruction helps Lucy 2.5 understand the edit. When using a reference image:

• Name the specific item, character, or style to use
• Describe the details that matter: color, material, texture, shape, pattern, logo placement, or fit
• Apply it to a visible target in the video
• Ignore unrelated reference details — the reference person’s face, pose, lighting, or background

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Prompt templates

Start with one of these structures, then add the details that matter.

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Character transformation

Use character transformation when the person in the video should become a different person, creature, or designed character. If you use a reference image, describe the character’s appearance in the prompt. “Replace the character in the video with <description of character>.” Examples:

• Replace the character with a silver-armored space explorer with a reflective blue visor, white gloves, glowing shoulder lights, and a short navy cape.
• Replace the character with a cheerful cartoon chef wearing a tall white hat, red neck scarf, double-breasted jacket, and round glasses.
• Replace the character with the person in the reference image, keeping their short curly black hair, gold earrings, green jacket, and warm smile.

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Add objects

Use add prompts when a new prop, accessory, object, or creature should appear in the video. Describe what to add and how it should relate to the subject or scene. “Add <description of object> to <where it should appear>.” Examples:

• Add a translucent blue hologram of a tiny city floating above the person’s open palm, casting a soft blue glow on their fingers.
• Add a red sequined cone hat with white fluffy trim to the person’s head.
• Add the plush green backpack from the reference image, attached to the person’s shoulders and shifting with their body as they move.

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Replace objects or features

Use replace prompts when something visible in the video should become something else. Name both the target and the replacement. “Replace <thing in the video> with <new thing or reference image subject>.” Examples:

• Replace the person’s sunglasses with oversized heart-shaped pink glasses from the reference image.
• Replace the person’s jacket with a glossy yellow raincoat with black buttons and a high collar. Keep the person’s identity, face, and hair unchanged.
• Replace the person’s nose with the carrot from the reference image.

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Change attribute

Use appearance prompts when the object stays in place but its visual qualities change: color, texture, material, pattern, lighting, or finish. “Change <object or feature> to <new color, material, texture, or style>.” Examples:

• Change the person’s sweater to red knit fabric with a small white emblem on the chest.
• Change the wall’s color to light blue with a smooth matte paint finish.
• Change the table surface to polished dark marble with subtle white veins.

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Remove objects

Use remove prompts when an object should disappear. For cleaner results, say what should appear in its place. “Remove <object>, leaving <what should appear in its place>.” Examples:

• Remove the soccer ball on the grass, leaving uninterrupted green grass in its place.
• Remove the coffee mug from the desk, leaving the wooden tabletop visible.
• Remove the poster from the wall, leaving a smooth white wall in its place.

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Change background

Use background prompts when the subject should stay visible but the environment should change. Describe the setting and what is happening in it. “Change the background to <scene with visible activity>.” Examples:

• Change the background to a Manhattan street scene with people walking on the sidewalk, yellow taxis passing, storefront lights, and soft afternoon shadows.
• Change the background to a beach scene with waves gently crashing on the shore and sunlight reflecting on the water. Keep the person’s identity, face, and clothing unchanged.
• Change the background to a snowy park where kids are playing in the snow and snowflakes fall through the air.

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Restyle the entire video

Restyle a video when you want a new art style across the whole clip. A restyle changes the entire picture at once, unlike a targeted edit. A strong restyle prompt covers four things:

• The style to apply
• Whether to change the whole video or just one part
• What the final video should look like
• Concrete visual traits: color palette, texture, line style, material, brushwork, or level of detail

“Transform the entire scene into <style>. The final video should show <specific visual traits>, while preserving the original subjects, layout, and motion.” Examples:

• Transform the entire scene into a watercolor painting style. The final video should show soft translucent color washes, visible paper texture, loose ink outlines, muted pastel colors, and simplified forms, while preserving the original subjects, layout, and motion.
• Transform the entire scene into an anime style. The final video should show bold clean linework, flat cel-shaded color blocks, vibrant saturated colors, and simplified backgrounds, while preserving the original subjects, layout, and motion.
• Transform the entire scene into a charcoal sketch style. The final video should show rough graphite shading, visible paper texture, loose hatching, and high-contrast black-and-white tones, while preserving the original subjects, layout, and motion.

Layered prompts combine multiple changes. They are easier to control when each change belongs to a different visual layer — background, person, clothing, object, or effect. “Change <background layer>. Change <subject layer>. Add <effect layer>.” Examples:

• Change the background to a colorful ice cream shop. Change the person’s hair to swirled vanilla soft serve. Change their shirt to a waffle-cone texture. Add colorful sprinkles falling around the person and bouncing lightly off their shoulders.
• Change the background to a moonlit forest. Replace the person’s jacket with a dark velvet cloak. Add small glowing fireflies floating around their shoulders.
• Change the room into a futuristic control center. Add a transparent helmet to the person’s head. Add soft blue interface lights reflecting on their face and visor.

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Common prompt mistakes

• Avoid process language. Describe the result, not the model operation.
• Avoid vague quality words. Words like “realistic,” “natural,” “seamless,” “cinematic,” “beautiful,” and “high quality” are less useful than concrete visual details.
• Avoid unrelated lighting or mood instructions. If you are changing a jacket, describe the jacket.
• Avoid several unrelated edits in one prompt. Test the outfit, background, hairstyle, and lighting changes separately before combining them.
• Avoid mixing several art styles in one restyle. Pick one style, describe its traits, and switch styles one at a time.
• Avoid identifying targets by frame position. Use visible details like color, material, pattern, text, logo, shape, or distinctive markings.
• Avoid negative instructions such as “don’t add a hat.” The model may still focus on the object you mention. Describe what you want to see instead.
• Avoid long event chains such as “bubbles float around the person’s head, pop into glitter, turn into birds, and fly into the sky.” Short physical interactions are easier to maintain.

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Dos and don’ts

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Troubleshooting