You are on the search for a publisher or incubator or investor for your game, and you’ve got your pitch deck all ready to go, but there’s something else you often need to convince outsiders of your magnificent vision: the vertical slice.

But just what is a vertical slice? Honestly, it’s right there in the name! Imagine you have a beautiful layer cake, and you’re going to give me a slice of it. Of course you’re going to slice all the way in from the top to the bottom, and give me a little bit of each layer, right? It’s not the whole cake, but from this one representative slice, I can pretty much guess what the rest of the cake is like.

That’s just what your game’s vertical slice should be doing: representing each “layer” of your game well enough that someone experiencing it has a good idea of what the rest of the game entails.

So what is each “layer” of your game, exactly? Layers can be thought of in two categories: If we stick with our cake metaphor, you can think of the cake (the gameplay, the art, the mechanics) and the icing that holds the layers together (meaning the systems, like UX/UI, the inventory, controls, etc.).

Your vertical slice should be a playable portion of your game that shows enough of the layers that the player—whether that be another developer you’re bringing onto the team, a publisher, or an investor—can understand the intended play experience of the game. If your pitch deck is making promises about what your game can be, your vertical slice should be backing all of that up with a clear, playable demonstration that delivers to some extent on each of those promises.

So what is a vertical slice not?

Perhaps to better understand what a vertical slice is, you can consider what one is not. A vertical slice is not your first playable build, and it is not your prototype. It is a build with clean, quality assets, polished UI, and the ability to be played (and understood and enjoyed) in one sitting. Your vertical slice should also be one more important thing: fun!

You want to be showing off something that works well in that it’s playable, polished, and enjoyable while being representative of the entire game. To do that, it’s best to include the following items, according to Xsolla.com:

• Art: Avoid placeholders a much as possible and show off your assets—literally!
• UI: Players should be able to navigate gameplay and menus easily and clearly.
• Mechanics: Try to show off all your main gameplay mechanics. That doesn’t mean every single weapon or minor ability, but if your character can fly, slow time, or walk through walls, you want to give the player the opportunity to see all those major mechanics in action so they can best understand the final product.
• Music: When’s the last time you watched a movie with no music? Probably never! Music is very important for setting a mood, and, while you don’t need the whole score yet, you want there to be some music in your vertical slice to help communicate the game’s atmosphere.
• Sound design: Sound effects are also a must! Include every one you can possibly have in there. They can help communicate the mood of the game as well as aid in immersing the player in your game’s universe, both of which are very important when “selling” the concept of your game.

And, if possible, you can also aim for these:

• Tutorials: As much as possible, you want your game to be able to stand on its own. Letting players know the basic controls at the very least is a good way to help them enjoy the gameplay and get the best first impression.
• Controller flexibility: When possible, include and communicate a player’s ability to play on a controller, a keyboard and mouse, and any other options you want to include in your final game.
• Settings/options: Building settings and other options into your vertical slice will add an extra layer of polish and ensure that those playing will be able to get the full experience regardless of their personal preferences.

Remember, a vertical slice is the first impression of your game and will inform what is understood and expected of the final product! It should prove that your game is fun and interesting and has good potential. It will also help demonstrate some of the issues that might come up in the future. (Which is good, so you and your team can tackle them early!)

Basically, your prototype answers whether you should make this game, and your vertical slice is meant to prove whether you can make this game. This is why investors and publishers want to see it: They want to see you prove it!

LTPF put it in more professional terms:

“To make a good Vertical Slice, you build some one of each thing (thing being vaguely defined, as every game has different needs) at a fidelity that approaches or convincingly simulates the shipping quality. Our goal is to run through the entire cycle from idea to implementation at least once, to see if there are any blockers, issues, or unforeseen complications in the creation of one slice, one functional segment of the game.

How ‘thin’ that slice is is really up to you: for a platformer, you could make one level, or you could make one tricky jumping section. For a shooter, it could be a tiny arena or an entire level. For a racing game, it could be a NASCAR track in the middle of nowhere or a super-complex city race with intersections and everything.

When you’ve completed the Vertical Slice, you should typically have identified a number of production issues in your pipelines, and taken steps to resolve them. You should also be clear on what the production process will look like going forward.”

If you want even further clarification, consider this video about the vertical slice from GDC a few years ago:

And with all of this, hopefully you feel prepared and capable of creating an excellent vertical slice that proves the value of your vision, the capability of your team, and the future potential of your latest project!

Do you still have questions about the vertical slice? Ask them in the comments below! Be sure to join our Discord server for more great discussions and insight.