The Item Index in Throw a Coin is the single most powerful long-term progression system in the game because it is the only luck source that grows in the background. The Roblox incremental simulator built by The BEST group yet! tracks every unique item you have ever pulled from the magic fountain, and every new entry adds a permanent luck bonus that stacks on top of your equipped coin, your Luck Multiplier upgrade, and your Perfect Throw bonus. The Index is the reason a long low-tier farm in World 1 is never wasted, the reason mutation runs are a smart move even on items you have already discovered, and the reason a veteran player with hundreds of Index entries can pull items a fresh save cannot.
There are 68 unique base items spread across the 24 rarity tiers, and each item has up to five mutation variants (Big, Huge, Rainbow, Astral, Divine) tracked as separate Index entries. A fully filled Index for the base items alone is 68 entries; a fully filled Index including every mutation variant of every item is 68 × 6 = 408 entries. The community consensus is that the base entries are the priority because they are the easiest to discover, and the mutation entries are a long-term goal that becomes accessible once the Mutation Machine (added in Update 3 on July 18, 2026) starts producing reliable outputs.
What the Index Tracks
The Index is divided into 24 sections, one per rarity tier. The first 19 tiers are mapped to specific coins, and the last five tiers (Primordial, Genesis, Beyond, Omega, Galactic) do not have a directly named coin but are reachable through deep-game play. Each section lists the items that belong to that tier, and a checkmark appears next to any item you have discovered at least once. Mutation variants of an item appear as separate sub-entries under the base item.
The Per-Band Luck Multiplier
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Common and Uncommon tiers fill in a single play session and provide the largest early Index luck bonus.
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Rare tier fills in the first day of consistent play and opens up the Luck Multiplier's meaningful range.
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Epic and Legendary tiers are the mid-game Index targets and are gated by the Fire and Volt coins.
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Mythic and Cosmic tiers are the late-game Index targets and are gated by the Aether and Starlight coins.
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Mutation sub-entries are filled by running the Mutation Machine and require four copies of the same item per entry.
| Tier | Coin | Items in Tier | Mutation Entries? |
|---|---|---|---|
| Common | Basic Coin | 5 (Soccer Ball, Rubber Duck, Alarm Clock, Apple, Traffic Cone) | Yes |
| Uncommon | Copper Coin | 5 (Chair, Gold Bar, Ping Pong, TV, Trophy) | Yes |
| Rare | Fortune Coin | 6 (Cash Bag, Treasure Chest, Wheel, Guitar, Piggy Bank, Magnet) | Yes |
| Epic | Fire Coin | 5 (Boombox, Anchor, Gem, Cash Register, Safe) | Yes |
| Legendary | Volt Coin | 5 (Arcade Machine, Crown, Fridge, Mjolnir, Grandfather Clock) | Yes |
| Mythic | Aether Coin | 5 (Azure Hypercar, Meeps, Nuke, Submarine, Tank) | Yes |
| Cosmic | Starlight Coin | 4 (Crimson Racer, Prism Shard, Rocketship, UFO) | Yes |
| Celestial | Galaxy Coin | 3 (Dragon Egg, Mona Lisa, Sailboat) | Yes |
| Eternal | Void Coin | 3 (Ornothopter, Superyacht, Private Jet) | Yes |
| Godly | Chronos Coin | 3 (Big Ben, Eiffel Tower, Pyramid) | Yes |
| Primordial | (no coin) | 1 (Void Compass) | Yes |
| Genesis | (no coin) | 2 (Satellite, Time Machine) | Yes |
| Quantum | Eclipse Coin | 2 (Quantum Cube, Impossible Cube) | Yes |
| Universal | Mirage Coin | 2 (Black Hole, Singularity) | Yes |
| Omniversal | Obsidian Coin | 2 (Infinity Door, Infinity Crown) | Yes |
| Absolute | Tempest Coin | 2 (Antimatter Reactor, Reality Core) | Yes |
| Stellar | Soul Coin | 2 (Mars, Moon) | Yes |
| Nebular | Paradox Coin | 2 (Saturn, Jupiter) | Yes |
| Beyond | (no coin) | 2 (Reality Throne, End of Reality) | Yes |
| Solar | Miracle Coin | 1 (Sun) | Yes |
| Zenith | Nexus Coin | 2 (Sirius, Spaceship) | Yes |
| Supernova | Apex Coin | 2 (Betelgeuse, Quasar) | Yes |
| Omega | Infinity Coin | 1 (Dyson Sphere) | Yes |
| Galactic | (no coin) | 1 (Milky Way) | Yes |
The Mutation Sub-entries
Every base item has five sub-entries for the five mutation tiers, and each sub-entry is unlocked the first time you produce a mutation of that tier. The most common first mutation is Big, so the Big sub-entries fill in first as you run the Mutation Machine on your early duplicates. The rarer mutations (Rainbow, Astral, Divine) fill in as you push deeper into the mutation ladder.
How the Index Luck Bonus Stacks
The Index luck bonus is a true multiplier on top of your equipped coin's base luck. The exact formula has not been published by the developer, but the community has inferred a roughly proportional relationship between the number of unique entries filled and the size of the bonus. The bonus never decays, so a single Index entry you filled in your first hour is still contributing to your luck in your hundredth hour.
The stacking position is third in the four-source stack: coin base luck, then Luck Multiplier upgrade, then Index luck, then Perfect Throw. Because the Index is in the middle, its effect is amplified by the sources above and below it. A player with 50 Index entries and a Fortune Coin and 10 Luck Multiplier levels has an effective base luck of 12 × 6 × 1.5 = 108x before any Perfect Throw, and a Perfect Throw on that stack is 216x.
The Best Farming Route for Index Completion
The community-recommended Index farming route is to work the tiers in order, starting with the lowest tiers and working up. The reason is that lower tiers fill quickly because the items are common, and the Index luck bonus you build up while filling the lower tiers carries over to the higher tiers where the items are rare. A player who fills the Common and Uncommon tiers in the first hour has a meaningfully higher Index luck going into the Rare tier than a player who tries to skip ahead to the Rare tier with a partial Index.
| Step | Tier | Approx. Time | Notes |
|---|---|---|---|
| 1 | Common (Basic Coin) | First 10 minutes | Free, fastest fills |
| 2 | Uncommon (Copper Coin) | First hour | First coin purchase |
| 3 | Rare (Fortune Coin) | First few hours | Duplicates become realistic |
| 4 | Epic (Fire Coin) | First day | Mutation runs become useful |
| 5 | Legendary (Volt Coin) | Mid-game | Push for first Mjolnir |
| 6 | Mythic (Aether Coin) | Mid-game | Mutation fodder becomes valuable |
| 7 | Cosmic onward (Starlight, Galaxy, etc.) | Late-game | Slow but steady |
Why You Should Farm Even After Moving Worlds
A common mistake is to leave World 1 as soon as you can afford the next coin and never return. The reason this is a mistake is that the Index is global: filling a Common entry in World 2 still requires pulling a Common item from a World 1 fountain, and the fastest way to fill the Common tier is to spend time in World 1 with a low-tier coin. The recommended pattern is to alternate between your current world (where the rare items are) and World 1 (where the common items are quick to fill), especially during long AFK sessions where the click cost is zero anyway.
Mutation as an Index Strategy
Running the Mutation Machine on every duplicate you collect is the single best way to fill the mutation sub-entries of the Index, and the bonus from filling mutation entries is meaningful because the sub-entries are counted separately from the base entries. A single base item with a full Big → Divine mutation chain contributes six Index entries (one base, five mutations) instead of just one, which is a 6x multiplier on the Index luck you would otherwise earn from that item.
| Item | Base Entries | Mutation Entries | Total Possible |
|---|---|---|---|
| Soccer Ball | 1 | 5 (Big → Divine) | 6 |
| Mjolnir | 1 | 5 | 6 |
| Milky Way | 1 | 5 | 6 |
| All 68 base items | 68 | 340 | 408 |
How to Verify Your Index Bonus Is Growing
There is no in-game counter that shows the current Index luck bonus, which is one of the most common complaints from new players. The developer has not published a tooltip or stat panel that shows the current Index luck value, so the only way to confirm the bonus is growing is to observe your drop distribution over time. The community-recommended method is to keep a rough log of your drops for a few hundred throws and compare the rarity distribution at different Index completion levels; the difference is usually visible in the rate at which new rarity bands start appearing for the first time.
A simpler proxy is the Index completion percentage shown in the Index panel itself. The percentage is the fraction of base entries you have discovered out of the 68 total base items, and it gives a rough indication of how far you have come. The percentage does not include mutation sub-entries, so a save with 100% base completion and 0% mutation sub-entries is meaningfully different from a save with 80% base completion and 50% mutation sub-entries, even though the percentage displayed is the same.
The 100% Base Index Milestone
Reaching 100% base Index completion is a meaningful save file milestone because every base item in the game is now contributing to your luck bonus. After 100% base, the only remaining Index gains come from mutation sub-entries, which require a steady supply of duplicates and a willingness to spend cash on the Mutation Machine. The community-observed effect of reaching 100% base is a meaningful spike in luck that makes the next coin tier noticeably easier to afford.
Frequently Asked Questions
Where do I find the Index in the game?
The Index is accessible from the main game menu, usually in the top-right corner of the screen. It opens a panel that shows all 24 rarity tiers, the items in each tier, and your discovery status for each entry including the mutation sub-entries.
Does the Index reset between Worlds?
No, the Index is global across all Worlds. An item you discovered in World 1 is still marked as discovered if you see it again in World 2 or World 3, and the Index luck bonus applies in every World automatically.
How many Index entries do I need before the luck bonus is meaningful?
The community-observed crossover is around 25 entries, where the Index luck bonus becomes large enough to noticeably shift drop rates. Below 10 entries, the bonus is negligible; above 50 entries, the bonus is one of the dominant luck sources for that save.
Should I prioritize mutations or base items for Index?
Both are worth filling, but the base items are easier and faster. The recommended strategy is to fill the base items as you encounter them, then run the Mutation Machine on duplicates to fill the mutation sub-entries over time. A fully filled base Index plus a partially filled mutation Index is a stronger setup than the reverse.
Does the Index track items that I sell?
Yes, the Index tracks every item you have ever pulled from the fountain, including items you have already sold. The discovery is permanent and unaffected by subsequent sales, so there is no reason to avoid selling items you do not need.