How Mello stays fair: seeds, safety checks, and ads

Deterministic Daily seeds

The Daily uses the UTC date to build a seed, then a fixed 30-piece sequence. Two players on the same UTC date receive the same sequence. The site does not personalize Daily difficulty based on your skill, spend, or ad history.

That design makes comparison meaningful and removes “the game hated me with different RNG” as an explanation for a shared day. Your placements remain the variable.

Endless bags and safety checks

Endless mode draws from a seeded piece bag so runs are reproducible from a seed rather than pure wall-clock randomness. Separately, a deterministic safety check may replace a tray the engine cannot verify as fully playable.

Important limits: replacement is not a hidden difficulty knob tied to your score, streak, or purchases. It exists to avoid dead-on-arrival trays the rules could already prove unwinnable. It is not a rubber-band that saves high scorers or punishes leaders.

What advertising never does

Google ads may appear on the website on approved pages. Forced pauses, when they appear after a long ad-free intro, are limited to eligible Endless post-run moments — not mid-placement, not mid-clear animation as a skill check, and not on Daily as a paywall for the shared day.

Ads do not change your pieces, score, combo, difficulty, Daily seed, or whether a move is legal. Optional remove-ads purchases suppress forced messaging; they do not grant better RNG.

• No mid-puzzle skill-check ads.
• No score-based piece buffs or nerfs.
• No paid luck or locked competitive themes that alter power.
• Daily seed identical regardless of ad state.

Accounts and privacy posture

You can play without an account. Optional sign-in uses Firebase for authentication and a limited score summary sync. Board saves and most settings stay on the device. Sharing results is something you choose after a run.

Account features exist for continuity of scores and streaks across devices, not for selling power. Deleting an account and clearing local storage are documented on Support and Privacy.

Why this matters for players

Block puzzles earn trust when improvement feels like learning, not like waiting for a lucky shop refresh. Mello’s rules, seeds, and monetization boundaries are written so that practice transfers: strategy guides stay valid tomorrow because the engine will not quietly rewrite incentives overnight.

If something ever looks wrong — a save wiped by private browsing, an outdated installed web app — Support covers recovery steps that do not include “watch an ad to restore fairness.” Fairness is restored by reloading the real game rules, not by a reward video.