How Developers Design Collectible Systems
A look at the decisions a designer makes when building a collectible system, and why each one exists.
Building a value ladder
The first decision is how many collectible types there are and what each is worth. Too few and there is no texture; too many and players cannot remember which is which mid-run.
Five to seven types with clear spacing works well. On this site the ladder runs coin at one, silver at two, token at five, gem at ten, star at fifteen and treasure at twenty-five. Each step is large enough that spotting a better pickup genuinely changes your route.
Each type also needs a distinct silhouette, not just a distinct colour. A player at speed reads shape faster than hue, and colour alone fails for players with colour vision deficiencies. On this site coins are circles, tokens hexagons, gems diamonds, stars stars and treasure a chest outline.
Value versus combo weight
A subtle but important decision is whether a collectible's contribution to the combo streak should equal its point value. It should not.
If a chest worth twenty-five coins also advanced the streak by twenty-five, a single chest would leap several combo tiers and the streak would stop measuring continuity. Decoupling the two lets a chest be worth a lot of points while advancing the streak by three, which keeps the combo a measure of how consistently you are collecting.
The same decoupling makes a decoy pickup possible: zero points, and a negative combo weight so catching one actively breaks the streak. Without separate fields that behaviour would need a special case in the scoring code.
Deciding what a magnet can touch
Every collectible carries a flag for whether magnet effects act on it, and the decision for each type shapes the game more than it first appears.
Cheap frequent pickups should be magnetisable. The magnet's job there is convenience, and it makes the game feel generous without removing any real decision.
The top-value pickup should not be. If a chest can be taken passively, the route to it stops mattering and the risk that justified its value disappears. This one exclusion is what keeps treasure meaningful in a game that also has magnets.
Decoys should never be magnetisable either, for the opposite reason: a magnet that drags a streak-breaking pickup into you turns a helpful power-up into a trap, which is a feel-bad the player cannot avoid.
Designing a fair decoy
Decoy pickups - items that look collectible and punish you for taking them - are a useful tool and easy to get wrong. The failure mode is making them too similar to the real thing, at which point the game is testing eyesight rather than judgement.
The rule that keeps them fair is that the tell must be visible on inspection but easy to miss on reflex. On this site the decoy is a cracked grey slug: the same size and shape as a coin, but a clearly different colour with a visible crack drawn across the face. A player who looks will always know; a player who grabs by reflex sometimes will not.
Decoys also need to be genuinely skippable. If a decoy falls in the same column as a valuable pickup with no way to take one and not the other, it is not a decision, it is a coin flip.
Layering feedback
Collection feedback should use several channels at once, because each does a different job.
A particle burst confirms the pickup registered, which matters most when the player is not sure whether they touched something. A sound whose pitch rises with the streak communicates combo state without requiring the player to look at the HUD - critical at speed. A floating number communicates value, which matters when types differ. A HUD counter provides the running total.
Rate-limiting the audio is a detail worth getting right. A magnet sweeping twenty coins in one frame will stack twenty oscillators into a click if unthrottled. Capping the sound to roughly one every thirty milliseconds keeps a sweep sounding like a run of notes rather than a noise burst.
Finally, all of this should respect a reduced-motion preference. On this site, particle effects are disabled entirely when the operating system requests reduced motion, and the audio and numeric channels carry the feedback instead.
Key takeaways
- A value ladder needs enough spread that types feel different, and few enough rungs that players can hold them in memory.
- Separating point value from combo weight stops one high-value pickup carrying a streak on its own.
- Excluding the top-value item from magnet effects is what keeps its route meaningful.
- Decoy pickups convert collection into recognition, and only work when the tell is visible on inspection.
- Feedback should be layered across visual, audio and numeric channels, because each communicates something different.
Frequently asked questions
How many collectible types should a game have?
Five to seven works well. Enough for texture, few enough that players can hold the value order in memory while playing.
Why give collectibles different combo weights?
So a single high-value pickup cannot leap several combo tiers on its own. It keeps the streak a measure of continuity rather than of luck.
Are decoy pickups unfair?
Only when the tell is not visible. A decoy with a clear visual difference that is easy to miss by reflex tests judgement; one that is nearly identical tests eyesight.
Why disable particles for reduced motion?
Because particle bursts are the most motion-heavy element in these games, and the same information is available through sound and numbers.
A note on terminology. Everything described as a coin, gem or treasure in this article is a virtual in-game collectible used for scoring. Nothing here relates to real-world currency, numismatics, collecting physical coins, or any form of financial value.
Alex Morgan is the editorial persona under which the guides on Coin Collector Arcade are published. Articles are written and reviewed by the team that builds the games on this site, and every mechanical claim is checked against the actual game code. Read more about our editorial team.