Monetizer Special: Analysing hard-to-soft currency conversion rates in F2P games that use a 'percentage fill' IAP economy

Delving into the guts of F2P monetisation techniques

Monetizer Special: Analysing hard-to-soft currency conversion rates in F2P games that use a 'percentage fill' IAP economy

Fool that I am, I hadn't realised F2P games were using variable hard-to-soft currency rates until a couple of months ago.

For research reasons, I started playing Capcom/Beeline's Snoopy Candy Town and quickly become fascinated by the variation in conversation rates between the hard currency (Beagle Bucks) and gold (the soft currency).

Like many of these games - which are becoming more popular - Snoopy Candy Town provides the option to fill your gold reserves (or safe) by different percent amounts; in this case 10 percent, 50 percent or 100 percent.

But because of the way the capacity of the safe changes over time, and the amount of gold in it, the ratio of the hard currency required to buy a certain amount of soft currency varies widely as you progress through the game.

This is particularly notable for the 10 percentage fill line where you get some outlier conversation rates because the minimum hard currency price that can be offered is 1 Beagle Buck.

In contrast, you get roughly the same conversation rate whether you perform a 50 percent or a 100 percent fill.

Digging down

Thus enlightened, I started looking for more games that use this monetisation technique and - of course - found lots of them.

Most embarrassingly, Clash of Clans has been using this technique and it's the game I played the most in 2012 and 2013. So much for being a monetisation detective.

The issues with a game like Clash of Clans, however, is that I've been playing it for so long, the ratios have become static. The variation is seen most strongly at the start of a game, so I found some other new games using the technique that I could start playing.

The first was EA/Mythic's Dungeon Keeper.

Unlike Snoopy Candy Town it uses a 25 percent (less outlier conversation rates), 50 percent and 100 percent system, and also unlike Snoopy Candy Town you get the most soft currency for each unit of hard currency if you're converting at the 100 percent level.

For Snoopy Candy Town this is reversed. In that game the 'best deal' always comes from performing a 10 percent fill.

Another difference is that Dungeon Keeper has two soft currencies - gold and stone. Interestingly, in terms of the conversation rate, both are similar. From my research, the 'worst' deal you could get was 200 stone or 200 gold per diamond (the game's hard currency) converted.

Looking at the graphs, over time we can see there's a considerable variation in the rate - roughly two-fold over a three week period. This means that players should avoid converting diamonds to soft currency in the early stages of the game, instead choosing to make such conversions when they have upgraded their stone or gold containers.

In addition, the best deals are always gained when you fill your containers (i.e. perform a 100 percent fill) although nowhere is this highlighted in the game.

Variation on a theme

After undertaking further research, we can see that it's Dungeon Keeper not Snoopy Candy Town which provides the industry standard model.

Like Dungeon Keeper, Nonstop Games' RTS game Heroes of Honor is set up to provide the 'best' conversation rate between its two soft currencies - gold and wood - and its hard currency (gems) when you perform a 100 percent fill.

Interestingly, though, while the graph for the wood conversation rate is similar to that which we see for Dungeon Keeper, when it comes to gold, the conversation rate drops from its initial value before rising again as you further upgrade your gold container.

Still more variation can be see in JuiceBox's HonorBound.

In this RPG, the conversation rate between the gold soft currency and the diamond hard currency for a 10 percent fill is a constant 20, as is the 50 percent fill (at just over 40) when you reach a certain point in the game.

Looking at the other soft currency - ember - the variation between the different fill percentage (10, 50 and 100) is tightly bunched and static compared to the other games. In addition, the conversation rate is much smaller than Dungeon Keeper (range 200-800) or Heroes of Honor (range 250-1,250).

A final studied game was Pocket Gems' RPG Epic Empire, which threw up the surprising conclusion that whether the soft currency (gold) was being converted as a 10 percent, 50 percent or 100 percent fill, the conversation rate with the starstone hard currency was fixed at 41 units of gold to one starstone throughout the game (although I only started recording having played the game for several months).


So what does it all mean? Good question...

As with all my Monetizer columns, I've stressed this is about a process to analyse and compare F2P games, not about drawing simple conclusions. On that basis, then, I'm just excited to have another tool with which to compare games.

Broadly speaking, however, I'd suggest that the use of variable conversation rates for percentage fills of soft currency reserves is a way for developers to better control their IAP economies.

To some degree, the fact you get a 'better rate' the higher the percentage fill you perform is a way to encourage players to spend more hard currency - a basic element of any F2P game.

Yet it's also a technique that is confusing for most players who aren't going to spend their time plotting graphs and who will likely assume they will get a similar deal for any conversion made. This isn't to say that such games are being manipulative, although I would label them as being 'more highly monetised' than games that use fixed conversation ratios.

This is something we can see when we consider a game's Discounted Currency ratio, which is the ratio of hard currency per dollar spent when comparing the minimum IAP transaction to the maximum.

Like variable conversation rates for percentage fills, the DCr is generally more generous the more money you spend on hard currency, but unlike variable conversation rates for percentage fills, developers typically highlight the fact to players that they get a 'better' deal the more they spend buying hard currency. That makes it less confusing.

It's also worth reiterating that of the games considered, Snoopy Candy Town and Epic Empire have a different approach, suggesting that there's still some experimentation going on in this area.

Something else I'm now looking at is the dollar cost of a percentage fill as a game progresses. This is still early research, but you can get an idea of what I'm on about in the following graph. 

And hopefully these two issues are something that we'll be able to further consider over the coming months.

Contributing Editor

A Pocket Gamer co-founder, Jon is Contributing Editor at which means he acts like a slightly confused uncle who's forgotten where he's left his glasses. As well as letters and cameras, he likes imaginary numbers and legumes.