Read This First: A Drip, Not a Flood
Rainbow Diamonds buy scouts — the draws that add characters to your roster — and they cannot be traded between players, so every free Diamond is earned on your own account. The sources below are the documented ones: missions, league seasons, events, logins and Bandai Namco’s own web store. Two honest caveats before the map. First, there is no fixed monthly figure: event and campaign calendars change the total month to month, and any guide quoting one is guessing. Second, the biggest single free hauls in this game’s history were anniversary campaigns — CBR’s coverage of the 7th anniversary notes up to 300 Rainbow Diamonds through dedicated login bonuses — so the calendar, not the grind, is where the spikes live.
Missions: The Daily Wage
The steady layer is the mission board. GamingOnPhone’s resource guide is blunt about it: completing daily missions is how players “gather Rainbow Diamonds,” and the harder missions are the ones that pay them. TalkAndroid’s league guide adds the Normal missions — the permanent checklist that newer accounts burn through for early Diamonds — and the Head Start login event, a 7-day starter track that pays Diamonds on set days.
Missions pay in more than Diamonds, and the rest matters to your roster: the same boards hand out the Bounty Coins, EXP orbs and skill orbs the leveling guide spends. Clear the daily board every day you play; it is the only source in this guide that is both daily and entirely within your control.
League Seasons: The Two-Week Payday
League Battle is the ranked core — 4v4 treasure battles that sort players into leagues from D- up to SS — and, per the One Piece Wiki, League Battles reset every two weeks, paying season rewards by final grade. The top of the published table shows what the climb is worth:
| SS league season reward | Amount |
|---|---|
| Rainbow Diamonds | 20 |
| 4★ character fragments | 50 |
| 3★ character fragments | 50 |
| Special Skill Orbs | 18 |
| Stat medal | ATK +160, DEF +130 or CRIT +14% |
Promotion pays along the way as well: TalkAndroid advises checking League Information in-game for the Diamond reward attached to each promotion, and pushing for the score target that triggers it. Even below SS, a finished season converts two weeks of play into Diamonds plus the fragments and orbs your leveling is hungry for — which is why league, not any side mode, is the farming backbone.
Challenge Battles, Boss Battles & Event Missions
Around the league sit the rotating modes. Challenge Battle follows the League format but requires specific characters to boost your score and ranks separately, per the One Piece Wiki. Boss Battle, in the game since August 2019, pits four players against a single AI-controlled enemy, and community coverage describes it as a monthly fixture with its own reward shop — the mode that keeps fragment-hungry players fed between seasons (see the leveling guide).
Event missions are the third tap: GamingOnPhone notes the Event section’s missions refresh on a monthly rhythm and “significantly reward the players with Rainbow Diamonds.” None of these modes individually rivals a league season, but stacked together — season, challenge, boss, event board — they are the difference between an account that scouts on schedule and one that is always 40 Diamonds short.
The Web Store & Account Linking: The Forgotten Faucet
The most-missed free Diamonds are not in the game at all. Pocket Gamer documents that the Bandai Namco Entertainment Web Store lets linked players “claim 5 Rainbow Diamonds for free each month,” and its webshop listings add a one-time redemption of 50 Rainbow Diamonds. Claiming requires linking your Bandai Namco ID in-game (Menu → Link Data), then redeeming on the store.
Linking pays on its own, too: Vortex Gaming’s update summary breaks down a recent 105 free Diamond bundle as enhanced account-linking rewards (50 for linking), web store bonuses (a further 50) and maintenance compensation. Maintenance Diamonds are occasional and unplannable — but the link and the monthly store claim are permanent fixtures that cost minutes, once. Do them before you optimise anything else.
Spend Discipline: Festivals or Nothing
- Save for Bounty Festival and EX banners. The game’s marquee characters arrive on limited scouts; Diamonds dripped into off-banner draws are the classic F2P regret.
- Count fragments as income. Duplicate characters convert into character fragments, so even a “failed” scout feeds grade-ups and Hyper Boost (leveling guide) — scout on banners whose duplicates you would be happy to own.
- Use tickets first. Draw tickets — GamingOnPhone lists Legendary Draw Tickets among the free resources — cost nothing to spend before Diamonds on the same banner.
- Anniversaries are the harvest. With campaign logins documented at up to 300 Diamonds, an account that plays daily through anniversary season out-earns months of ordinary play.
Buying Rainbow Diamonds & Accounts
Diamonds themselves cannot be bought from other players — there is no transfer system — so third-party “cheap Diamonds” means someone logging into your account, which is the risk pattern to avoid. Legitimate Diamonds come from the in-game store and the official web store. What players do trade is whole accounts and boosting, and those markets are compared on our One Piece Bounty Rush page — check the vendor ratings there before spending anything.
Frequently Asked Questions
What is the best free source of Rainbow Diamonds in Bounty Rush?
League seasons are the backbone: leagues run D- to SS and reset every two weeks, with SS paying 20 Rainbow Diamonds plus 50 4-star fragments, 50 3-star fragments, 18 Special Skill Orbs and a stat medal, per the One Piece Wiki. Daily and normal missions are the steady layer underneath, and anniversary login campaigns are the spikes — up to 300 Diamonds in the 7th anniversary campaign.
How do I claim the web store’s free Rainbow Diamonds?
Link a Bandai Namco ID in-game (Menu → Link Data), then redeem on the Bandai Namco Entertainment Web Store. Pocket Gamer documents 5 free Rainbow Diamonds every month from the store, plus a one-time 50-Diamond redemption; linking itself paid 50 Diamonds in a recent update bundle, with 50 more via the store.
Do league rewards reset in Bounty Rush?
Yes — League Battles reset every two weeks, and season rewards are paid on your final league grade. That fortnightly cadence is what makes league the farming backbone: every season is a fresh payout of Diamonds, character fragments and skill orbs.
Can you buy Rainbow Diamonds from other players?
No. Diamonds cannot be transferred between accounts, so any third-party Diamond offer involves account access. Buy through the in-game store or the official web store; whole accounts and boosting are the actual player market, compared on our Bounty Rush page.
Sources
Checked October 18, 2026. Game systems change with patches, so confirm numbers in game.
- One Piece Wiki (Fandom): One Piece Bounty Rush — league grades D- to SS and season rewards
- Pocket Gamer: One Piece Bounty Rush redeem codes — and the web store’s free monthly Rainbow Diamonds
- GamingOnPhone: ONE PIECE Bounty Rush — Tips to obtain Resources easily in the game
- TalkAndroid: One Piece Bounty Rush Guide — 9 Tips, Hints and Strategies for League Battles
- Vortex Gaming: Bounty Rush update summary — the 105 free Rainbow Diamonds breakdown
