Here is the test for slides built to support a speech: if your audience can read your slide and stop listening to you, the slide has failed.
I’ve watched thousands of speakers over the years, and the pattern is depressingly consistent. The speech is good. The slides are detailed. And every time a new slide appears, the audience reads it, finishes reading it about 12 seconds before the speaker finishes talking about it, and then mentally checks out for the rest of that section. The speaker keeps talking to a room of people who already moved on.
Slides for a speech are a fundamentally different design problem than slides for a report or a deck someone reads on their own. The rules below are how you solve that problem.
Rule 1: One Idea Per Slide. Always.
This is the rule that fixes 70% of bad slide decks. One slide should communicate exactly one idea. If you find yourself fitting two ideas onto one slide because you are running out of slides, you are running out of slides because your speech has too many ideas.
The fear most people have is that this means they need 80 slides for a 20-minute talk. It doesn’t. A good speech-supporting slide stays on screen for 30 to 90 seconds. Some sections of a speech don’t need any slide at all (more on that in Rule 5). A 20-minute speech might have 15 to 25 slides, and several of those will be the same dark blank slide.
One idea per slide forces a useful constraint: it makes you write the speech first and the slides second. Which leads to the next rule.
Rule 2: Write the Speech Before You Open PowerPoint
If you open PowerPoint first, you will end up writing your speech to fit your slides. That is exactly backward. The speech is the thing your audience came for. The slides exist to serve the speech.
The actual order:
- Write a rough version of the full speech, in plain text, the way you would actually say it
- Read it aloud, time it, cut anything that doesn’t earn its place
- Now mark the moments where a visual would help your audience understand or feel something they couldn’t get from your voice alone
- Those marked moments are your slides. The rest of the speech needs no slide.
Almost nobody does this. Almost everyone opens PowerPoint, builds 12 bullet-point slides, and reads from them on stage. If you do steps 1 through 4 instead, you’ll be in a tiny percentage of speakers who actually use slides correctly.
Rule 3: No Sentences. Maximum Six Words.
The six-word rule isn’t arbitrary. Reading a sentence takes about 3 to 4 seconds. During those 4 seconds, your audience is not listening to you. If you have 20 slides with full sentences on each, you’ve taken away over a full minute of attention from your own speech.
Six words or fewer can be glanced at and absorbed in under a second. The audience’s attention returns to you immediately. Examples of slides that pass the six-word test:
- Three options for retirement income (4 words, sets up the section)
- Sales doubled. Costs stayed flat. (5 words, communicates a key finding)
- The decision is the easy part (6 words, makes a counterintuitive statement that you’ll explain)
If you absolutely must include data, like a quote, statistic, or formula, that’s fine. Just make sure it’s the only thing on the slide and use type large enough to be read from the back row (more on that next).
Rule 4: Type at Least 36pt for Anything Anyone Needs to Read
The general rule of thumb: take the age of the oldest person in the room, divide by two, and that’s the minimum font size in points. For most professional audiences, that’s around 36pt. For older audiences, 44pt or more.
Why this rule matters: people in the back of a room of 100 chairs are sitting about 40 feet from your screen. Text below 36pt is unreadable from there. So if you put a 24pt sub-bullet on your slide, you’re guaranteeing that half your audience can’t read it. They will spend the next 30 seconds squinting and failing to read it, which means they will not be listening to you.
The fix is simple: if it’s not big enough to read from the back, leave it off the slide. Say it out loud instead. Your voice carries everywhere your slide can’t.
Rule 5: Use Blank Slides Liberally
The single most underused tool in speech-supporting design is the blank dark slide. A pure dark gray slide with no content on it. You should have several of these scattered through your deck.
When your speech is in a moment that doesn’t need visual support, the slide should disappear. A dark blank slide does exactly that. It signals to the audience: look at me right now, not the screen. The room’s visual focus snaps back to you, which is where it should be during the emotional or persuasive parts of your speech.
Most people leave the previous content slide up because they don’t know what else to do. That content slide keeps competing for attention while you’re trying to land a punchline or build to a key point. A blank slide solves the problem.
In PowerPoint, you can also hit the B key during a presentation to instantly black out the screen. W for white. Both are useful tools for the same reason: returning attention to the speaker.
Rule 6: Show, Don’t Describe
When a visual is genuinely needed, it should be visual. A photograph, a chart, a diagram, a single sentence in big type. Not a bullet-pointed list describing what the visual would look like if you had bothered to include one.
Examples of where to use real visuals:
- Before-and-after comparisons. Two photos, side by side, no text. Let the contrast do the work.
- A statistic. One huge number on a blank background. “42%” in 200pt type lands harder than “42% of customers churn within 6 months.”
- A complicated process. A clean diagram with three arrows, not a paragraph of explanation.
- A person being discussed. Their photo, their name, nothing else.
If you’re not sure what visual to use, here’s a useful default: a high-quality, full-bleed photograph that captures the emotional tone of what you’re saying, with no text on it. The photo does the visual work. Your voice does the rest.
Rule 7: Pick Two Colors and Two Fonts. That’s It.
Speech-supporting slides should look like one consistent visual identity, not a collage. Pick two colors and stick with them across every slide: usually a dark background color and one accent color. Pick one font for headings and one for body text. Done.
The reason for the limit: visual variety on slides creates cognitive load. Every time the audience sees a new style, a tiny part of their brain spends a second processing the change instead of listening to you. Keep the style identical across every slide and that distraction disappears.
Need help picking? Our guide to the best fonts for presentations covers proven font pairings, and our presentation color schemes guide includes hex codes you can copy.
Rule 8: Never Read Your Slide Aloud
If a slide says “Three Reasons Why,” do not say “Three Reasons Why.” The audience can read. They’ve already read it. Repeating it makes you sound like a presentation robot.
What you say about the slide should add something the slide can’t. Context, story, the human moment behind the number, the implication of the comparison. The slide is the headline. Your speech is the article.
This is one of the hardest habits to break because it feels safe. Reading the slide means you can’t forget what you were going to say. The cost is that your audience perceives you as someone who is reading rather than thinking. If you need a safety net, write the next sentence on a notes card you hold, not on the slide everyone else is looking at. We’ve got more on this in our piece on how to present without reading your slides.
The Order I’d Build a 15-Minute Speech Deck In
Putting it all together, here’s the actual sequence I follow when I’m helping someone build slides for a speech:
- Write the speech in plain text. Time it. Cut to fit.
- Mark the 8 to 15 moments that need a visual.
- Open PowerPoint. Pick a dark background, two fonts, one accent color.
- Build each visual slide one at a time. Six words max, or one image, or one big number.
- Insert blank dark slides between sections.
- Rehearse the full speech with the slides advancing. The slides should feel invisible. If you notice a slide pulling attention away from what you’re saying, fix it.
- Do it again. Three rehearsals minimum.
One last thing. The speakers who get standing ovations rarely have the most beautiful slides. They have the slides that get out of the way. Your audience didn’t come to watch your slides. They came to listen to you. Design your deck like you believe that, and the speech will land.
