The Rule
Light School has a rule for campus lessons: under 80 lines of content. Not 80 lines of code. 80 lines of actual content. That is the ceiling.
When I first started writing lessons, I thought this was too restrictive. Some topics felt like they needed more room. But after writing dozens of guides, I think this might be the most important rule we have.
What Happens With Long Pages
When a reader opens a page and scrolls down to see how long it is (and they always scroll down to check), one of two things happens. Either they think "okay, I can finish this" or they think "this is going to take a while."
The second reaction kills the lesson before it starts. Not because the reader is lazy. Because they are busy. They have ten minutes between meetings. They are checking this out on their phone during lunch. They will come back to it later, they tell themselves. They never come back.
Short Pages Feel Different
A short page sends a message before anyone reads a word. The message is: this will not take long. You can do this right now. You will finish this and feel good about it.
That feeling of "I can finish this" is more powerful than any headline or introduction. It is permission to start. And starting is the hardest part.
But What About Complex Topics?
Some things are genuinely complex. You cannot explain everything about a tool in 80 lines. And you should not try. The answer is not one long page. The answer is two short pages.
Break the topic into pieces. Teach one thing on the first page, the next thing on the second page. Each page stays short. Each page feels achievable. The reader finishes one and moves to the next because they are on a roll.
Two pages that people finish are worth more than one page that people abandon.
What I Have Learned
The 80-line rule forces me to be clear about what matters. When you only have 80 lines, you cannot waste any of them on filler. Every sentence has to earn its place. Every paragraph has to move the reader forward.
The constraint makes the writing better. And more importantly, it makes the page something people actually finish.
