‘Energy’, a design concept popularised by that one-time pariah of the traditional game industry, Zynga, is now employed by developers the world over in their games, the most recent and high-profile examples being last week’s CSR Racing on iOS (currently the number 1 title in both the UK and the US) and Sim City Social, a Facebook-based remake of the PC classic.

For the uninitiated, ‘Energy’ is a unit of currency used to limit the number and rate of actions a player may perform in a game. For example, a single race in CSR Racing will cost you 1 unit of ‘Energy’. You are free to race as many times as you want while you have ‘Energy’ but the moment you run out you may no longer participate. Instead, you must wait for your ‘Energy’ to refill over time (at a rate dictated by the designer), or you can pay real money in order to refill the gauge immediately.

For a player in the midst of an exciting and engaging experience, the frustration of being told they must wait for their next ‘move’ is, oftentimes, a keen enough incentive to hand over cash in order to keep playing.

Some games choose a different metaphor (e.g. ‘Petrol’, in CSR Racing), but always this nefarious unit’s function is the same: to prevent a player from playing the game until they have either paid to do so or until they have sat in the corner as punishment for being a skinflint for the sufficient length of time.

For social and free-to-play games, which allow their players to enjoy the game gratis, ‘Energy’ is an ostensibly reasonable way to monetise the experience and earn the game’s stakeholders some money for their efforts. It is in fact so effective, that many of the most successful and highest-earning games on the App Store employ this funding model.

It has, in a few short years, become one of the most disruptive and effective design concepts to hit the game industry. And yet it is also one of the most pernicious. ‘Energy’ is fundamentally a design to limit the player’s enjoyment and freedom in order to earn the creator money, rather than a design to increase the player’s enjoyment and freedom in order to earn the creator money.

It’s a subtle distinction that is worth unpicking.

Apologists claim that the model is analogous to the arcade industry in the 1970s and 80s. Here ‘Credits’ not ‘Energy’ were required to extend the player’s experience. As Martin Amis wrote in his 1982 book ‘Invasion of the Space Invaders’: “As the accountants at Williams Inc. know full well, you have to spend a LOT of money to get good at Defender.”

But there is a difference between the energy of ‘Credits’ in the arcade industry and ‘Energy’ in current games, one perhaps best expressed in Pac-Man.

In the original arcade game, you would pay your 50 cents and play the game until Pac-Man lost his lives at the wispy hands of its ghoul attackers. The business exchange between game player and game creator was clearly defined and stated: the player’s actions were limited not by some artificial, esoteric currency but rather by her own skill.

You paid your ‘Energy’ up front and then, if you were skilled at the game, you had the opportunity to extend your turn. That business dynamic in and of itself is fun. Excel at the game and you get more for your money (except, of course, you must pay in order to gain the necessary skills and strategies required to excel). This was Pac-Man’s business model.

By contrast, if Pac-Man had been designed around the ‘Energy’ business model, everyone could play for free but every pellet you ate would reduce your energy by one (after all, masticating can be hard work).

After eating 25 pellets the game would pause and you would be told you had a choice: wait for five minutes for the gauge to refill, or pay 50 cents to fill it on the spot. Theoretically you could complete Pac-Man without ever spending a nickel: it would just take you three weeks.

So you gain something in the design (for one thing, everybody would have a go at Pac-Man – after all, it’s free). But you lose a whole lot more in doing so. No longer can I get ‘more’ for my money. No longer do I gain a skill in the process. Rather, it’s a design purely to generate more money from the player, at the cost of something much more valuable.

‘Energy’ has introduced a queuing system to video games where there was no need for one. It creates a class system within players: those who pay and those who do not. It artificially bloats the design, and makes murky where the true value and enjoyment in an experience is to be found. Moreover, it inspires game designers to spend their own ‘Energy’ in designing money-making systems, diverting attention and resources from the design of enriching, challenging, enjoyable play systems.

It is, unquestionably, the worst design innovation in our medium to date, apparently creating effective money-making products, but at the cost of artistry, and a regrettable shift in design focus.

At one time, this innovation was easy to ignore, an irritating development in a cousin state to video games’ true home. But every week it nudges closer to the heartland, as the designers behind some of the best games our industry has produced (from Split/ Second to Sim City) choose to adopt this most negative of energies.