Ratopia DevDiary #18 - Trade and Exchange

5 Sep 2023
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Hello all, it’s Cassel, developer of <Ratopia>. 

We participated in this BIC (Busan Indie Connect) and had a fruitful exhibition. 

Thanks to the improving exhibition environment and supports, 

it was great to be able to interact with various fans, developers, and gamers in a relaxed setting.

Had great time enjoying those unique games with brilliant ideas

There were many impressive games with distinctive features at this BIC. 

I hope that <Ratopia> becomes captivating enough to be showcased abroad as well. 

In that spirit, in this DevDiary, on this time, I will detail the international trade system of <Ratopia>.

The World Map

Prior to talk about trading, I have to talk about the world map. 

In <Ratopia>, players will encounter cities other than their own settlement. 

We wanted to enable players to gain economic benefits through interactions with these cities. 

However, we couldn’t significantly increase the number of tiles the player character can roam, 

because frequency of moving characters to distant locations could create significant gaps in city management. 

And thus the world map and exploration features were born.

Once the city stabilizes to a certain extent, 

players can send scouts on the world map to explore. 

Initially, only areas adjacent to the player’s city are available for exploration. 

After sending scouts to the target area and waiting for a certain period, 

the exploration is completed, and the surrounding areas will become available for further exploration.

When explore continues one region at a time, 

cities of rats that are hiding from plague rates and predators will be found. 

We intended to have a newly generated world map for each game and vary the exploration time depending on the destination, 

making the players contemplate their exploration priorities.

Newly made world map page using the old research page

Unfortunately, this did not make players think at all. 

It was because they could simply explore the places with the shortest exploration time to quickly discover cities. 

We still needed mechanisms to provide motivation for exploration, 

such as rewards that can be obtained beyond finding cities, 

or events that can occur depending on the destinations.

It would be nice if the explored regions provided clues that could influence the decision for the next destination, 

but I’m still deliberating because there are many problems that seem difficult to resolve simply. 

If we want to provide clues about surrounding areas, multiple user interfaces must be clearly presented, 

and to make players deduce based on revealed clues, the world map might need to expand.

How can we improve the joy of expedition as <Civilization> and <Curious expedition>? 

Getting back to the point, 

players can establish diplomatic relations with other cities they discovered through exploration. 

In <Ratopia>, about 20 cities are planned, 

and in each game, approximately half of them are placed on the world map according to certain rules. 

Most of these cities view the player’s newly established city unfavorably, 

so in order to forge deep relationships, it’s necessary for players to invest a significant amount of their treasury to increase goodwill.

 Currently, the only way to increase goodwill is by gifting money, 

but in the future, we intend to add methods to boost goodwill through events or through citizens engaged in diplomatic activities.

Explore and diplomatic system of old version <Ratropolis>. Hope it works out this time! 

When the relationship is good enough, now the trade function opens. 

Although not yet implemented, we also intend to add features like forming alliances to jointly resist invasions, 

or engaging in hostile acts to conquer opposing cities.

There are many elements we wish to add to exploration and diplomacy. 

However, given the current trend of its design serving largely as a foundation of the next step – trade, 

we’ve decided, albeit regretfully, to implement only the bare minimum functions for now and plan to enhance them later on.


Trade, the essence of economic management games, I’d say, has been developed from the outset. 

Due to the map size constraints in <Ratopia>, the game structure inherently limits resources. 

Even after clearing the entire map, there was a need for an avenue to purchase or exchange resources.

However, upon integrating the trading feature, 

we realized there were more considerations than initially anticipated. 

Since players could easily obtain necessary resources for their city through trade, 

the motivation to establish settlements to procure rare resources diminished significantly. 

For instance, if iron ore was needed, rather than seeking out mineral-rich mining territories, 

players would first consider simply buying it through trade. 

However, making it overly challenging to acquire resources via trade was also not an option. 

We had to strike a balance, ensuring it was just the right amount of difficulty.

Hedgehog with trading cart. It’s a secret, but it can fly.

I wanted the players to not just trade essential resources on a one-off basis as needed, 

but to consistently trade certain resources in line with their city’s development direction and the international market conditions. 

To guide players in this direction, a few mechanisms needed to be introduced.

Firstly, we delayed player’s access to resources they can trade. 

We limited the types of resources available for trade to a maximum of five kinds per city. 

For premium resources, trade would only become possible once some time had passed and the city had developed. 

This was done in hopes that players, after establishing and advancing their cities and understanding the overall situation, 

would strategically determine which resources were truly essential.

Next, we made the resource prices vary for each city, giving them different market rates. 

As time passed, the prices of tradable resources would rise or fall. 

This meant that even when trading the same quantity of resources, 

players could either incur a loss or see greater profits compared to previous trades. 

However, which such price fluctuations, one-time trades became advantageous during favorable market conditions. 

So, we introduced agreements where trades occur periodically for a set number of times based on the current price. 

Additionally, if players tried to alter or terminate the agreement prematurely, they’d face a penalty. 

This made players calculate which option would yield the greatest benefit.

Lastly, we made the arrival time of traded goods vary depending on the distance. 

The resources would not be immediately exchanged in the storage after an agreement, but only after a certain period. 

The time taken would increase based on the distance between trading cities on the world map. 

This shifted the game structure: instead of easily resolving resource shortages with a few button clicks, 

if players did not calculate their demands and stock up in advance, they could potentially face a crisis.

Are you following leader?

With the introduction of these diverse elements, we are building a rather satisfying trade system. 

However, I am concerned that it has also become more complex. 

Furthermore, we must continuously be cautions during development to ensure 

that the wealth generated from trade doesn’t become so significant that it renders other systems meaningless.

Dar and Exchange

‘Dar’ is the basic currency used by the rats in the world if <Ratopia>. 

As the player explores the world map, the player will come across cities that trade exclusively in Dar. 

Players must construct a bank to exchange ‘Pia’ for ‘Dar’ at the current exchange rate. 

From this point on, players will have to deeply consider when it is most profitable to trade based on the exchange rate.

However, if you don’t like delving into such considerations, there’s a lighter approach. 

You can simply capitalize on arbitrage by using currency exchanges to inflate your national treasury, 

and then dominates the world with massive capital. 

While the exchange rate is linked to trade, it can also be utilized separately from trading.

The exchange rate in <Ratopia> is not designed to fluctuate based on complex economic logic like in reality. 

Instead, we wanted to make it dependent on luck so that players could enjoy it lightly. 

Accordingly, we designed the exchange rate to change through a drawing mechanism that many people like. 

Every day, a random exchange rate ticket is drawn from a draw box and then put back in. 

The drawn ticket indicates a percentage value, and the exchange rate changes by that amount. 

In addition, we allowed players to add desired exchange rate tickets to the drawing box based on their choices in events. 

This way, they can indirectly influence the direction of the exchange rate. 

Can’t lose the deck-building!

The challenge was how to represent these exchange rate tickets and a way to show the fluctuation of the exchange rate. 

While the rules are simple once understood, it was not easy to explain to beginners. 

Including the values, durations, etc., on an icon was challenging due to the small size of the icon. 

Consequently, there were a lot of considerations and changes regarding the layout of the exchange page and the ticket.

UI development, still a far way to go

Just like with trade, increasing national wealth through these exchange rate profits is enjoyable, 

but we don't want it to overshadow the charm of other parts of the game due to excessive gains. 

Therefore, if there are many exchanges, we are adding various compensatory measures, 

such as making the exchange rate shift in a direction unfavorable to the player, or encouraging trade through the currency "Dar."

As we kept adding fun features, some unexpected issues arose. 

But what can we do? 

With no previous experience, we need to dive in, face these challenges, and find solutions. 

If you have any interesting ideas about trade and exchange rates, please leave them in the comments. 

If an unforeseen problem arises, we'll get in touch.

This development log might feel a bit rigid since it's based on a static screen. 

In the next development log, I will introduce the boss battles and dungeon system. 

I hope everyone has a great September, and happy Autumn holidays. 

(Come to think of it, I’ll probably be writing a DevDiary during the holidays.)

STEAM: https://store.steampowered.com/app/2244130/Ratopia/

FACEBOOK: https://www.facebook.com/CasselGames/

X (TWITTER): https://twitter.com/CasselGames

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