NOTE: This article targets small to medium sized F2P productions.
Lets start with: don’t write a painfully long document enclosing a ton of details and explanations of each and every parcel of your game. This “doc” needs to paint a broad picture of your idea, be easily searchable, updateable, understandable, referenceable – that’s all!
To achieve such feat, i would suggest using a tool such as Confluence and avoid standalone docs (wherever possible).
As a structure, i would segment into:
Main target and idea
What’s the target audience, what’s the fantasy, why should i play the game, how is your game standing out from the crowd, what’s the one line sentence that can define the gameplay experience.
Primary and Secondary features
All games have features, some are critical to the product some not that much. Nevertheless, understanding the differences between them is of utmost importance to your game’s success.
In an ideal setup, all of these will find their place in a complex web of interdependencies, allowing the user to connect the dots and understand the relationship between them.
In short, if you manage to intersect them in such a way that using the great majority of them is linked with successful player progress, then you are surely one step closer to building a great game.
Out of that, i would further branch the “Primary and Secondary” features into relevant sectors:
Gameplay
Retention
Monetization
Meta Loop
Simply said, what am i building / upgrading / pouring resources into at the end of my play cycle? In all F2P games you grind for some XP, resource, item or currency or you simply play over and over again to complete the level saga / map entries while spending energy. No matter the grind, you will always channel its outcome towards building your meta, be it to upgrade your heroes / cards or beautifying your garden / zoo / mansion or simply progressing stage after stage in that never-ending ladder of levels.
Core Loop
Also known as the grind, is the cyclic pattern the player needs to undertake in order to advance in the game’s meta. For simplicity’s sake, use diagram / flowchart tools to better illustrate the loop – i personally use Gliffy.
The core loop can simply be illustrated by a Play – Loot – Upgrade repetition where you will ideally replace the three elements with the previously identified Primary and Secondary features.
For instance, this would be the Core Loop for the F2P game Empires & Puzzles
Economy Loop
There’s nothing fancy and complicated about an economy loop, not at this stage at least. All you have to do is mark down the locations that grant currency/items and the ones that spend them. The main idea is to have a fair understanding of generators and spenders, so that your Progression and Balancing design properly integrates them in your loops.
You wouldn’t want to generate a need for spending resources without having a means through which you gather them, and you surely wouldn’t want the vice versa, having too many resources without introducing a purpose for using them.
Progression and Balancing
These are two of the most important areas of a F2P game and will make the difference between a successful or unsuccessful game. Make it too easy for a player and he will probably get bored after a couple of day’s play, make it too difficult and he will think twice before opening the game for a second time.
This is not something new, and anyone who has played more than a handful of games will easily understand the concept, yet this goes into a whole different ball park when it comes to free to play.
The main areas you need to look after are gameplay and economy, for which you will be interested in having a skeleton for both balancing and progression. Values will of course not need to be final, yet having this doc early on will allow you to better envision how your game will shape up.
For instance, lets say you build an RPG, you will of course need to know how much team power you need in order to win a level and what would the reward be for level 1 vs level xxx. Or maybe you have a Hidden Objects game, how will the first encounter differ from the 100th, how many items do you have on the screen, what’s the timer looking like, how much energy do you consume for playing the level, things like that.
I know it may sound like you’re doing a lot too early, yet these should not take you much time to build, you can simply sketch the “backend” of your game through a simple spreadsheet. My choice is the very powerful Google Sheet & Google Script combo.