How to Write a Script for a Comic Book
To write a script for a comic book, start by creating an outline to capture your story's major events. Then, use it to develop either page description lines or panel description lines, which provide guidance to the illustrator about how various parts of the comic should appear. Next, craft captions that provide story information beyond what you want the illustrations to convey. After that, write dialogue for your characters and give the illustrator directions on how to transition from one panel to the next.
Decide if a plot first script is right for you. Plot first scripts, often called "Marvel style" scripts due to Stan Lee's preferred style, leaves out a lot of the detailed instruction and gives that creative license to the artist or illustrator. There are exceptions, of course, but typically a plot first script is chosen when the writer and the artist have a strong rapport from previous projects, or when the writer will also do his own illustrations, in which case the script serves more as an outline for what the artist/writer anticipates will happen. A plot first script will typically include the characters, narrative arc, and page instructions. This type of script generally leaves the details of the script, such as the number of panels, the arrangement of panels, and the pacing within the page, to the illustrator's discretion. Often times the particulars of a scene, such as dialogue and captions, are added by the writer after the illustrator has created the art and broken the various scenes down into their panels. Unless you intend to write and illustrate your comic, a plot first script works best when the writer and illustrator have worked together in the past and trust one another's vision for the comic. Devise a plot line. A plot first script doesn't have to be as detailed as a full script, as the script serves as more of a template or outline of the comic's narrative arc. But there are still important decisions to be made, and a writer working on a plot first script must think in terms of storylines for the current issue as well as future issues of the comic. A plot first script typically focuses on the characters and story arc involved in a given comic's issue. The script will focus on which characters are involved in that issue, what will happen to each character, and may include some notes about how the characters will interact with one another in that issue. Once the script is written, the artist illustrates the panels. Because the plot first script is so minimal, the writer often ends up giving the artist extensive liberty to determine how events unfold, and at what pace. Write dialogue to fit the panels. Once the artist has illustrated the panels, the writer reviews the panels and writes dialogue to fit the sequence of events that the artist has depicted. The writer's dialogue is limited by the space provided for caption bubbles and by the imagery that the artist has chosen. For this reason, it is worth reiterating that plot first scripts work best when the writer and the artist have worked together in the past and have a shared vision for the style, format, and story arc of the comic. Choose a script format. Unlike screenplays, there is no single standard format for full script comics. You may choose to follow a screenplay format, or you may wish to mimic the script format of a comic series that you really enjoy. Or you as the writer may choose to create your own format that makes the most sense to you. However you choose to format your script, be sure that it includes the following: unambiguous directions that the artist will be able to follow visible page and panel numbers indentations or other visual cues in the script for dialogue, captions, and sound effects Decide on a page layout. Once you've decided how you want the script to be formatted, you may want to take a bit of time to determine how you want the comics to visually appear on the page. Just as there is no single standard format for a script's format, there is no single page layout that a comic must follow. Some comics progress from left to right like written sentences. Other comics use larger, page-wide panels that progress from top to bottom. Still others use entire pages as a single panel. Some comics will use one page layout - say, a series of panels read from left to right, top to bottom - and then throw in some variance for dramatic effect. A common tactic is to suddenly shift to a panel that takes up an entire page, for dramatic effect. This might happen during a dramatic death, an unexpected betrayal, or anything else that will shock or surprise your readers. Write an outline. Once you begin writing the script you'll significantly expand the ideas and develop your characters more thoroughly, but when you're starting your script it may be helpful to have an outline. This allows you to have a reference of your original intentions, in case you get too deep into expanding and developing. It also gives you a bare bones template that can help you plan out how a given issue's plot and story arc will relate to other issues of your comic. Start by writing a single sentence for each turn of events in the story. Add in some brief notes on which characters are involved in each major event, and how those characters relate to one another. If you have ideas planned out for future issues of your comic, connect your notes for the current issue with other single sentence plot points for the future. Think visually. Once you've plotted out your story's outline, you'll need to start planning for the script itself. Before you begin writing the script, think visually about the outline you've created. Don't just restrict yourself to the main sequence of events. You may choose to give a lot of creative license to your illustrator, or you may decide to give visual direction to the illustrator on how to depict the setting of your comic (including whether that setting's ambiance changes from day to night or from season to season). You'll also need to come up with concrete visual images for things like establishing shots, character closeups (including the style of dress and any traits or quirks of characters), and the general feeling you want readers to have about each character and the environment they inhabit. The best way to train yourself to think visually as a comic writer is to read a wide variety of comic books and graphic novels. Look closely at the style of each comic and the details given in each panel. Think about what kinds of written direction you would need to give an illustrator for him to design that scene/panel/character. Write description lines. The description lines will instruct the illustrator on how various parts of the comic should appear. This can be tricky, as it requires you to combine the visual imagery you've envisioned with detailed written instructions to the illustrator. Common directions given in description lines include instructions for the establishing shots in a given comic, closeups of characters or images, and background imagery. There are two common methods of writing description lines: Page description provides the illustrator with the setting, mood, characters, and action sequences that are to appear on each page of the comic. The illustrator then decides how many panels will appear on each page, and chooses how best to represent those instructions in each panel. Panel description gives detailed instructions to the illustrator on how each panel should appear, and what should happen in each panel. Some writers even recommend to the illustrator how to frame each "shot" of each panel. Highlight significant visual elements. The writer should mention specific details about any visual elements that are important to the plot. This may include meaningful objects, characters who will be relevant later in the story, and even what season or time of day a given panel takes place in. Give any relevant information that the artist will need before drawing out each scene, such as time of day, expressions on characters' faces, and any objects or environmental details that will be significant later in the comic. Write captions. Captions can be thought of as the voice of the disembodied narrator who informs readers of where the action is taking place, or providing "voice overs" during meaningful events in the comic. They appear in square or rectangular boxes, usually at the top or bottom of a comic panel. Captions should work in conjunction with the images drawn by the artist to help inform the reader or to elevate the reader's experience of the comic's narrative arc. Write captions in the order they should appear in the finished comic. Avoid captions that simply repeat or reiterate the visual cues from the comic. In other words, don't use captions to tell the reader what would otherwise have been inferred from looking at the comic. Write dialogue. Dialogue is the actual conversations and soliloquies that characters speak during the course of the comic. Dialogue boxes are often depicted as a round or oval-shaped bubble, usually with a small "tail" to a character's mouth to indicate that that character is speaking. Characters should appear in a panel in speaking order. In other words, the character on the left should talk first, with her dialogue bubble appearing above any subsequent dialogue bubbles. If two characters have a back-and-forth conversation, the character on the left should speak first, and the character on the right should respond with a dialogue bubble below the first speaker's text. One lengthy dialogue bubble or conversation between two or more characters should be contained in a single, still frame. Don't try to cram too much dialogue into one panel. Rather than cramming a panel so full of conversation that it blocks out the characters, you may want to opt for a back-and-forth conversation where one panel shows a closeup of one speaker (and her dialogue), and the next panel shows a closeup of the other speaker (and his dialogue). Once you've written your dialogue, read it out loud. Like any written dialogue, it may sound different when heard out loud, and you may notice some lines are difficult to read quickly or sound weird when paired with the action in that scene. Always read your dialogue out loud, and ask yourself if the dialogue (when heard out loud) conveys what it should be conveying in the scene. Don't get bogged down in verbal writing. The primary characteristic of a comic is the visual element, so remember the old adage, "less is more." Write the action. This part of the script may be most similar to a film script in that it gives extensive detail about what will actually happen during the course of a comic. Some successful comic writers recommend writing for yourself first, and the audience second. In other words, don't compromise your vision for what your comic should look like because of what you imagine people do or don't want to see. Write a comic that you'll be satisfied with, and if it's a sincere and meaningful comic to you, it will most likely be meaningful to your audience. Each panel should develop a character or further the narrative story being told. In other words, don't be wasteful with your panels, and make the action count for something in your story. Remember that the primary action of your comic will be visual. As you write the action for the script, don't get too text-heavy. Just provide the illustrator with sufficiently detailed instructions on how the action should look. Write transitions for your comic. Once you've written the action, dialogue, and captions, you'll need to write how the illustrator should transition the comic from one panel to the next. This is important, as poor transitions can make the comic feel choppy, inconsistent, or even confusing. Regardless of the comic's pace, each panel should flow together smoothly and seamlessly. Some common types of transitions include: Moment to moment transitions - the same person, object, or scene is shown in succession across multiple panels, with each panel showing a different (but not too distant) moment.This may be useful for showing transitions in mood as one character relays information to another character, for example. Action to action transitions - the same person, object, or scene is shown in succession across multiple panels depicting different - yet still related - actions. This may be useful as a sort of visual montage to show the passage of time as a character trains for a fight or embarks on a journey, for example. Subject to subject transitions - each panel depicts a different person or object, across a continuous scene. This is useful for breaking a longer conversation into smaller dialogue panels. Scene to scene transitions - the two panels in this type of transition show entirely different scenes, which may take place in differing environments or time periods and may depict different characters or actions. Aspect to aspect transitions - each panel in this type of transition shows different aspects or elements of the same place, people, or action. Non sequitur transitions - this type of transition makes a drastic jump from one scene to the next without any apparent continuity or connection from one panel to the next. Because of the potential for confusing readers, this type of transition is very rare in most comics that follow a continuous narrative arc. Choose your comic's duration. Do you see your comic being a stand-alone story, or part of a larger narrative? Does your comic's narrative follow a single person, a group of people, or multiple generations of people? All of these are important factors to determine before you try to get your comic published. If you go through a publisher, they will most likely want to know before publication what you see for the future of your comic. Knowing the "mythology" of your comic's universe will help you find a publisher who will make your dreams for your comic come to life. Explore your publishing options. There are many different publication routes a comic writer can take. Which route you choose will depend on your vision for your comic, what kind of audience you realistically see the comic appealing to (niche audience or mass appeal), and whether you'd prefer to work with a smaller "indie" press or a larger publishing agency. Each option has its advantages and disadvantages, and no single choice is necessarily "better" than any other. Search for different comic publishers online and read about each publishing press's submission guidelines, contractual obligations, and monetary compensation. You should also look into whether or not a given publishing press accepts unsolicited manuscripts. Compile a proposal package. Once you've done your research and you know what kind of press you'd like to work with, you'll want to put together a proposal package to send to a given publishing press. Include your name and contact information on every page of the package, in case any pages are lost or separated from the package. A good proposal package will include: a cover letter that addresses the editor of a press by name and includes all of your contact information, as well as what your comic is generally about a written "elevator pitch" that summarizes the plot of your comic a detailed plot outline and elaborate character biographies a rough estimate of your comic's length, format, and any ideas for future story arcs an introduction to your comic's setting (which is particularly important to know in the case of science fiction or alternate reality comics) a full script or, at minimum, a sufficient sample of your script to give the editor a good idea of how your comic will appear and what type of story it will be any illustrations you or an outside artist have come up with for your characters, setting, or action sequences any relevant copyright/trademark notices 
Decide if a plot first script is right for you. Devise a plot line. Write dialogue to fit the panels. Choose a script format. Decide on a page layout. Write an outline. Think visually. Write description lines. Highlight significant visual elements. Write captions. Write dialogue. Write the action. Write transitions for your comic. Choose your comic's duration. Explore your publishing options. Compile a proposal package. 