RNG Heroes Hero Rarity Bands and Gacha Pool

RNG Heroes is named for the gacha pull: every roll spends Gold for a chance at a fantasy Hero whose role fills one of your active hero slots. The developer has not published a drop-rate table or a Luck-to-probability formula. This page documents the community-observed rarity bands, the size variants, and the Index Gem economy, and it keeps every unverified percentage clearly labeled as rumor.

The community-observed rarity ladder

The Earnaldo gamepass guide and the NerdsChalk gold guide describe the same qualitative ladder. None of the percentages below are developer-confirmed; they are the community-observed balance that emerged from the late-July 2026 UPD 4.2 build.

The official description confirms the headline mechanic of rolling rare POWERFUL Heroes and fighting monsters, but the developer does not publish a rarity table.

Luck is a redistribution, not a flat bonus

The community-observed behaviour of the Luck stat matches the monotone-likelihood family p_tier ∝ w_tier * (1 + alpha * Luck)^k_tier. The intuition is:

• A +1 luck point does not add a flat percentage to every tier.
• It moves probability mass from lower to higher tiers in a way that keeps Common dominant.
• The effect on Mythic is the most visible; a Luck scalar above ~5 visibly raises the Mythic hit rate during a 50-roll session.

The Luck_Total scalar that the formula reads from is the sum of every Luck source on the account:

Luck_Total = BaseLuck
           + TreeLuck         (Luck upgrade, Player branch Luck I/II)
           + PrestigeLuck     (Prestige Luck I, +100%)
           + IndexLuck        (+10% per Index Gem spent on Luck)
           + GamePassLuck     (Lucky +1, ULTRA Lucky +5, VIP +1)
           + PotionLuck       (Luck Potion, Size Luck Potion)

The free Heroplay Studios Roblox group bonus contributes +1 Luck and stacks on top of every other source.

Size variants: Huge, Giant, and Colossal

Huge, Giant, and Colossal hero variants are layered on top of an existing tier; they are not a separate rarity band. The AllThingsHow progress guide and the NoobBlox beginner walkthrough describe them as size-shifted variants that are gated by:

• The Luck upgrade and the Player branch’s Luck I / Luck II.
• The Max Giant Chance and Colossal Hero Chance Prestige nodes (the developer does not publish the exact effect magnitudes).

Every new discovery of any of these variants drops an Index Gem, so the size ladder is also a Gem source: keep auto-roll on, keep the inventory visible, and bank the variants as you find them.

The Index Gem economy

Index Gems are the discovery reward that bridges the hero pool, the enemy pool, and the size variants. They are earned by:

1. Discovering a new Hero (any tier).
2. Discovering a new Enemy in a new biome.
3. Discovering a size variant (Huge, Giant, Colossal).
4. Discovering a Golden enemy variant.

Each Index Gem is a permanent, account-wide boost. The four Index upgrades are each 1 Gem per level, with effects that stack on every other permanent source:

The Earnaldo gamepass guide and the AllThingsHow progress guide both recommend the Luck Index upgrade first, then the Gold Index upgrade, then the Damage Index upgrade. Roll Speed is a low-priority spend because Prestige Roll Speed is more cost-effective in the early cycles.

What the wiki does not publish

• The exact drop-rate percentage for any tier or size variant. The Earnaldo guide and the AllThingsHow guides both call these percentages unverified.
• The exact Luck -> DropProbability mapping. The p_tier ∝ w_tier * (1 + alpha * Luck)^k_tier family is a model that matches the observed behaviour; the constants are not developer-confirmed.
• The complete current Hero roster. The community descriptions stop at “Warrior (Common starter), Assassin (Rare from Beginnings), Samurai / Mage / Ranger / Tank / Healer (named roster from late-game rolls)” and at the unnamed Common filler; the developer has not published a full list.
• The exact Prestige node effects that gate the size variants (Max Giant Chance, Colossal Hero Chance).

The Upgrade & Luck Scenario tool is the way to model your own Luck scalar against your own Gold balance, and the codes status page is the source for the bundle rewards that hand you a free Rare hero at the very start of the game.