[This text, on the crucial aspects of virtual goods design, is an extract from the ninth chapter of Social Game Design: Monetization Methods and Mechanics, by Tim Fields (Certain Affinity) and Brandon Cotton (Portalarium). In the book, the two authors closely examine how social games function as a player-responsive business.]
The very phrase "Virtual Goods" is something of a delightful contradiction. Anything "virtual," by definition, doesn't physically exist, and goods, at least when appearing within the context of the marketplace, are typically an article of trade.
For our purposes, though, virtual goods are real enough that they generate billions of dollars in revenue each year, and are so important to players that they can drive binge play sessions, provoke real-world fights, create (and destroy) marriages, and keep users spending money twenty-four hours a day, in almost every country in the world.
Virtual goods may be an amusingly 21st century contradiction in terms, but they're also big business, and a major part of social and mobile game design.
Virtual goods can end up taking on many different forms in a game. They can be literal items which a player or character buys in order to enhance their in-game abilities, or they can be instantly consumed "items" which grant the user more turns, or access to some previously-unavailable feature.
They can also be purely cosmetic items which stroke a user's vanity by letting them customize the way their character or car or card or farm animal appears to other players. These items can be a core component of gameplay, or they can be special, even seasonal items.
We'll discuss popular items of all types, and talk about how such items can be used to affect, alter, or destroy a game's balance. We'll discuss how to avoid some of the game-balance pitfalls often created by offering functional items for sale, and ways to make visual customization features appealing to your users as a way to distinguish themselves from the crowd.
If a game is going to monetize via the sale of virtual goods, it's ideal for the game design to account for this from the moment of the game's inception. To be well executed, the game's designers need to plan in advance what types of items will be sold, and understand very clearly the ways in which these items will affect the game balance. Virtual items need to augment the gameplay, not distract from it.
The best types of virtual goods are those which fit nicely into the game world, and act as a core component of each and every move. In a city-building game, each different building the user interacts with could be considered a virtual good. In an online driving game, the subcomponents of the user's car can be the basic building blocks of the virtual goods system. For a first person shooter, each gun or bullet could be a purchasable item, and so on.
What all of these examples share in common is that the goods for sale are a critical component of almost every user's experience within the game system, and they were designed from the onset of the game to play a major role in every second of the user's experience.
Integrating the sale of virtual goods into an existing game design is difficult to do without inadvertently "breaking" the game. At best, the system is likely to feel like a tacked-on afterthought designed to extract money from customers without improving the gameplay. The best way to avoid this type of design afterthought is to carefully identify which parts of your game design could reasonably rely upon the sale of virtual goods, and which parts need to remain untangled from the influence of microtransactions.
Spend time analyzing other games in the market and take advice from there; would Monopoly be as much fun if you could just throw a dollar on the board every time you wanted to buy a hotel? Determine what you're going to sell for real money, and carefully integrate that plan into your overall game design.
Team Fortress 2 by Valve is a free-to-play FPS on Steam which monetizes by selling virtual items. Games can sell items that are either functional, cosmetic, or both.
For game designers, there is a core division between the two key types of virtual goods, and this distinction needs to be understood from the onset of the design process. In-game items (or even non-item boosts, accelerators, or features) need to be considered in terms of the degree to which they alter gameplay for the user.
Purchases that change something meaningful about the game are said to confer "functional advantages." Purchases that are purely aesthetic are often no less important to users, but they serve a different function in the game's design and moment-to-moment play. These purchases are generally considered "vanity items."
There are many types of goods that can grant a functional advantage in a game. In a shooter, this could be something as obvious as a more damaging gun, or a gun that fires faster than those available in the game for free. In a city-building game, a functional advantage could be a certain type of bulldozer that produces new buildings faster than is possible for those players who do not chose to spend real world money. Role playing games tend to favor swords and armor; for a fishing game... well, you get the idea.
When considering selling players items that give them a real advantage in gameplay, game balance should be a critical consideration. If rich players are overpowered, those who don't spend money, or as much money, will become disenfranchised and quit playing. Alternately, if players don't feel engaged because a game is too easy or too hard, they'll quit playing. There are a few ways to overcome this, and since the core problem is a different depending on the type of challenge offered in the game. First, there are some general issues to consider for items of this type: