By Tamir Nadav, Head of Creative at Kokku
It's been a while, so I figured I should write a little about some game design tricks I've used. This is about how to balance game economies, specifically for games that have a grindable mechanic (RPGs, Rogue-Likes, etc). When playing these games, you'll often find a lot of various currencies to keep track of: XP, EP, SP, Gold, Silver, Lumber, Tokens, Bananas, you name it. Balancing all of this to make sure that players of all skill levels have good (if not quite uniform) experiences can be a challenge. This is where it becomes helpful to compound all your currencies into the two true variables they are: Time, and Milestones.
The Currency of Time
Most currencies are really just an approximation of play time. Think about it like this - if I go into the dark forest and beat up every dark imp I find, I can earn on average 100g per hour. I will also earn a slightly rarer currency of 20 silver per hour. So, after 5 hours of grinding, the average player will have 500g, and 100 silver. Now, the merchant in town has all the latest and greatest gear for the party, and equipping everyone with what they need to move forward will cost in total 1200g, and 300 silver. What you can see is that it'll take roughly 15 hours of grinding in order to hit the silver need, and they'll have some gold left over.
The more currencies you add, the more complicated this can get. The more various ways you have to purchase things, the more complicated this can get. But, you can always compile everything down to time, and see where you are. In the example above, now imagine that during that grinding you get 30xp per hour. Over the course of 15 hours of getting all that gear, the player will then get 450xp. Let's imagine that this is enough to bring your characters up from the average level of 10 at this point in the game, to level 14. Look at the stats of your playable characters at level 14, combined with the gear purchased above. How strong/weak are they? Are they ready for your next area?
(BTW: Please do not put 15 hours of grinding into your game in a single area. That's not nice.)
Players invest time in games, and expect to be rewarded for it. All of these various currencies allow you to create various purchasables (weapons, armor, skills, levels, land plots, etc), and with all of them having time as a common factor, means that this will always be a useful technique to manage expectations.
The Currency of Milestones
There is a second type of currency: Milestones. Let's see if you can find the milestone in this super awesome weapon of coolness: 5000g, 400 silver, 300 timber, 45 diamonds, 10 rubies, and 1 Crystalized Heart of an Undead Lichqueen. Did you spot it?
Milestone currencies are currencies that cannot be grinded, they can only be earned. They are gates, if you will. In the above example, in order for the player to get the CHoaUL (I'm not writing it out again), they need to defeat the Undead Lichqueen. Milestone currencies are great for two purposes:
To reward a player for completing a specific task, or
To prevent a player from progressing too much (or slowing down progression) in a particular area.
In the first case, milestones tend to be for particularly challenging encounters. They then earn the ability to create a legendary weapon or armor, or access a bonus area, earn an achievement, or something similar. In the second case, these act as hard blocks for progression. Essentially, if I could stay in the first area of a game and grind indefinitely, I could theoretically never need to worry about my currencies again. But with milestones attached, players are encouraged to continue the story or play through particular areas in order to proceed, even if to proceed to areas where grinding yields better results.
Additionally, milestone currencies become incredibly important in games where crafting or creation play a bigger part. In order to grow your farm from Lv 2 to Lv 3, you need a golden seed, only acquireable by defeating the Golden Hawk up on the cliffside. Even if you were able to acquire 99 of every variety of plant in the game, you can't plant them without leveling up your farm and unlocking the plots necessary to harvest them.
Time and Milestones Together
Integrating these two types of currencies are what gives players a reason for just one more battle, or to check out one more area, or to try one more run. They go from immediate rewards (single combat encounter) to permanent improvements (legendary gear, stat growth). They are trackable (usually) for the player, and generally speaking, easy to implement on the technical side (gold += 100).
Another great benefit of evaluating game currencies using Time and Milestones during development is how much it helps both pacing and balance when used correctly. The number of games I've played where I can one hit kill an enemy group in one section and then get TPK'd in the next is quite high. By properly examining where players are, what their average strengths and weaknesses will be, and how much time you would like them to spend in each area will help craft the numbers for you. Milestones will help give the players direction, and prevent their power levels from getting out of control.
Final Thoughts
I firmly believe in the importance of time balancing in gaming, but particularly in games like these. While Roguelikes can have 10-30 hour completion times, RPGs tend to expect player commitment of 40 to sometimes hundreds of hours. If you're asking for that investment from players, it's important to make sure they can enjoy that experience all the way through.
What do you think? Do you use systems like these in your game balancing?