Reverse engineering Block Blast: The free puzzle game that makes $213M per year
- $213Ma year from ads, estimated
- 1B+downloads on Google Play
- 4.8stars from 5.7M reviews
Revenue: industry analysts' estimate of about $584,000 a day, via Udonis, June 2026 (annualised by us). Downloads and rating: Google Play, October 2026.
The 50Fold team found that Block Blast doesn't deal your pieces at random. It picks them from "recipes", and one recipe makes you instantly lose your game.
Industry analysts estimate the game makes about $584,000 a day from ads (Udonis, June 2026). By our math, that's about $213 million a year. It has over a billion downloads on Google Play.
We wanted to know how a free puzzle earns that, so we used the 50Fold engineering agent to reverse engineer the app.
1. Your next three pieces come from a "recipe"
What we found. Every turn, the game uses a series of recipes to determine what pieces to give you (algoList). The game ships with 126 of them, with titles like:
- Fill the gap and clear: about 60 recipes.
- Plain random: 9.
- Hard puzzle, stop score farming, revive and lethal question (
24001).
What decides which recipe you get each turn isn't in the code we read.
What it means for you. A bad hand isn't always bad luck. Each set of three is built by a recipe: easy, hard or impossible.
Why it matters. "Random" is the minority. Most of the recipe book is tuning.
What a small team can ethically copy this week.
- Separate your game routes. Write each kind of challenge as a separate file, so you can tune and test them one by one.
- Make most of them helpful. Block Blast's biggest group helps you clear lines.
2. Death block: three pieces you can't place
What we found. One recipe runs a function named death block, typo included (func_death_blcok). It:
- Splits the pieces into ones that fit your board now and ones that fit nowhere.
- Picks 2 that fit and 1 that fits nowhere.
- Tests the orders you could play them in, clearing lines along the way.
- Keeps the set only if no order places all three, then shuffles it.
What it means for you. When death block runs, the three pieces can't all be placed in any order. Unless you watch an ad to revive, the run ends there.
Why it matters. A losing hand is a built-in recipe, not a fluke or random outcome.
What a small team can ethically copy this week.
- Protect the start. In the first two rounds, Block Blast checks your three pieces and swaps any set that would end your game (the code's log calls it "round keep-alive").
3. What the app sends about you
What we found. Before many ad loads, the ad engine sends a pricing model a profile. The default version carries:
- Your phone: RAM, total storage, maker, device type.
- Your setup: carrier, system language, network type, app version.
- You: days since install (
active_days) and what your last ad earned (last_ecpm).
A second version adds your country (cat_country). The model answers with a predicted ad value and floor prices: the minimum an advertiser must pay to show you the next ad.
Hungry Studio's US privacy policy discloses device model, language, storage, network and ad-interaction data.
What it means for you. Your phone and your ad history help set the minimum price for the ads you see.
Why it matters. The ad side runs on a profile of each player, built mostly from the phone.
What a small team can ethically copy this week.
- Say what you send. List the fields your app shares with ad partners, in plain words.
4. The record-run ad
What we found. In endless mode only (ENDLESS_GAME_TYPE = '0'), for players whose ads have paid above a server-set bar (high_value_threshold), a rule fires when either is true:
- Long run near your best. The run has lasted longer than a server-set time, and your score is above a server-set share of your high score (
cur_score > high_score × highest_score_proportion). - Big plays. Your combo or board clears pass a server-set count.
Then the next ad shown is the best-paying one loaded (pickBestEcpm). It covers pop-up and rewarded ads. The thresholds aren't in the app.
What it means for you. A high-value player on a long run near their best can get the best-paying ad the app has.
Why it matters. It times the top ad to the run you care most about.
What a small team can ethically copy this week.
- Hold ads until the habit forms. The same engine has seven rules that keep pop-up ads from new players, such as none until a set number of finished games (
block_game_num).
5. The daily ad tolerance score
What we found. The app keeps a daily score for each player around pop-up ads (our name: ad tolerance score). It starts at 10 (DEFAULT_BASE_SCORE = 10) and adds 1 for each new session that day.
- Normal close: +1, however soon you close it. Three in a row: +2 more.
- App killed while an ad is on screen: the score drops by how long the ad was up.
| Ad on screen when the app is killed | Score change |
|---|---|
| 0–3 seconds | −5 |
| 3–10 seconds | −3 |
| 10 seconds+ | −2 |
The lower the score, the likelier your next pop-up ad comes from a server-set list of ad networks:
| Score | Chance the list is used |
|---|---|
| Below 0 | 100% |
| 0–5 | 80% |
| 5–10 | 50% |
| 10–15 | 30% |
| 15+ | 0% |
It changes which loaded ad you see. It never changes how many ads you get.
What it means for you. How you've reacted to ads today decides which network serves the next one.
Why it matters. A per-player, per-day read on ad fatigue, from four numbers.
What a small team can ethically copy this week.
- Set a daily friction budget. Score each user's day, and keep your worst moments away from users near the limit.
- Bench partners that make users quit. When 2 of the last 5 ads from one network end in what the code calls an escape, that network is benched for 2 hours (
DEFAULT_COOLING_TIME_MINUTES = 120). - Grade advertisers on completion. An advertiser whose ads are finished less than 60% of the time, over 3+ shows in 7 days, gets its selection score cut to 0.8× (
DEFAULT_DOWNGRADE_FACTOR = 0.8). Its ads aren't priced lower; they just win less often.
6. A country table by install age
What we found. The app ships a table of 53 countries (COUNTRY_ECPM_DICT), with a pop-up and a rewarded value for three install ages. The code gives no unit. United States:
| Days since install | Pop-up | Rewarded |
|---|---|---|
| 0–6 | 44.85 | 84.06 |
| 7–30 | 26.15 | 43.41 |
| 31+ | 21.84 | 34.66 |
Brazil's first week: 4.28 and 6.01. The US rewarded value is 14 times Brazil's.
It's a benchmark, not a price. When the server turns it on (useCountryEcpmDict), floor-price rules compare your recent ad results with your country's row.
What it means for you. Where you live and how new you are set the bar your ad results are measured against.
Why it matters. In every country, the first week has the highest values.
7. Every rule has a server switch
What we found. Every rule above is off unless the server sends its switch (fsw_502, rvw_502, bsw_501, fsw_503) plus an inner flag (score_priority_enabled, useCountryEcpmDict). No switch from the server means off. The ad engine can also download a newer version of itself (CAN_UPDATE).
We can't see which players get which switch.
What it means for you. What runs on your phone is switched on from their server, and can change without an app update.
Why it matters. The app is a box of rules. The server decides which ones are live.
What a small team can ethically copy this week.
- Ship dark. Build features with a safe default of off, then switch them on for a test group from your server.
Our verdict
In our view, Block Blast is less a game of skill or luck than an ad delivery system disguised as a puzzle game.
To be fair, most of its recipes help you clear lines, the first rounds are protected, and much of the ad engine shields players: new players are kept from ads, and networks that drive people away get benched.
What to copy
- Protect early rounds. Never let a new user lose on turn one.
- Hold ads until the habit forms. Wait for finished games, not the first launch.
- Bench partners that make users quit. Track which ones drive users away, and rest them.
- Set a daily friction budget. Count each user's bad moments and stop before the limit.
What never to copy
- Death-puzzle modes. Better to design a game that allows randomness to end a player's game rather than forcing it while players assume it's random.
How we read it
- The 50Fold engineering agent reverse engineered Block Blast 10.8.6 for Android, in October 2026.
- We read the parts that ship unencrypted: the piece library, the ad engine and plain config files. The game's own scripts are encrypted, so we make no claims about them.
- The app ships default settings its server can change. The findings describe what ships in the app; live values may differ.
- 50Fold is not affiliated with or endorsed by Hungry Studio, Block Blast's developer.
This research is used to build the 50Fold Method.