Gems & Star Ranks Guide: 9 Gem Types, Star Rituals & Hero Multipliers

Bomb Farm's star system has one confirmed rule: you earn stars on an item by fusing duplicate copies of it, and this sits alongside the +0 to +15 upgrade track and sealed-drop reveals as the game's three gear-power layers. As of September 2026, no official Bomb Farm source (Steam store page, developer notes, or Steam Community discussions) documents a list of 9 gem types, a 'Star Ritual' mechanic, or a numeric hero star multiplier, so any guide quoting specific gem names, per-star percentages, or ritual costs is unverified. This bombfarm wiki page lays out exactly what is confirmed about stars, roles, and progression, marks the gaps clearly, and gives a practical framework for deciding which heroes and items deserve your duplicates first.

What Stars Actually Are in Bomb Farm (Verified)

According to the Steam store description written by developer Stream On, gear power in Bomb Farm comes from three stacked layers: revealing sealed drops, upgrading items from +0 to +15, and collecting stars by fusing duplicates. Stars are therefore a duplicate-consumption system, not a separate currency you buy. When a second copy of an item you already own appears in a reveal, that copy becomes fusion fodder for the original rather than clutter.

The store copy also describes a fourth goal, 'chase the perfect attribute', which implies that items roll variable attributes on reveal. In practice this means an item has two independent things worth checking before you fuse it away: its star progress and its rolled attribute quality. Fusing a high-roll duplicate into a low-roll original is the most common way idle-RPG players waste value, so compare attributes first and keep the better base.

What the sources do not state is the star cap, how many duplicates each star costs, or the exact stat bonus per star. Treat any numbers you see elsewhere for these three values as unconfirmed until Stream On publishes them or you verify them in your own inventory screen.

• Sealed drops must be revealed before you know what item (and which attribute roll) you received.
• Upgrade track runs +0 to +15 and is separate from star rank.
• Stars come only from fusing duplicate items into an existing copy.
• Star cap, duplicates-per-star, and per-star bonus: not published in any current source.

The '9 Gem Types', Star Rituals, and Hero Multipliers: What Is Not Confirmed

Searches for a bombfarm wiki often lead to pages promising nine named gem types, a ritual that converts gems into hero stars, and a flat multiplier per star. None of this appears in the Steam store description, the Steam Community General Discussions or Trading boards, or any developer announcement available as of September 2026. The game launched on 28 August 2026, so third-party wikis have not yet caught up, and the model behind this guide has no training data on the game either.

Specifically, the following are unverified: the existence of a gem system at all, the number 9, any gem name or color, whether gems drop from rocks or reveals, whether a 'Star Ritual' screen exists, and any formula tying hero star rank to a percentage stat boost. If you have the game installed, the reliable way to check is to open the hero detail panel and the fusion or upgrade menu and read the tooltip text directly.

This page will be updated once Stream On documents these systems or once enough independent Steam Community threads confirm the same details. Until then, the safe assumption is that the only confirmed star source is duplicate fusion described in the previous section, and that heroes may or may not share that mechanic with equipment.

• Unverified: 9 gem types, gem names, gem drop locations, gem socketing rules.
• Unverified: any mechanic named 'Star Ritual' or 'Star Ceremony'.
• Unverified: per-star hero multiplier values or stacking order with base stats and gear.
• Confirmed only: stars via fusing duplicates (equipment context, Steam store page).

Hero Roles and Abilities: Which Heroes to Invest In First

Bomb Farm heroes fall into four roles listed on the Steam store page: Attacker, Support, Collector, and Specialist. Each hero has unique attributes and abilities, and the game ships with 20 abilities in total, each upgradeable from level 1 to level 10. Because ability levels and star ranks (if heroes have them) are separate investments, the question of 'who to star first' is really 'whose abilities does my active team depend on'.

The store page also states that you switch between three teams to keep the mine running nonstop. This is the single most important fact for prioritisation in an idle game: a hero who only appears in one of your three rotations delivers roughly a third of the uptime of a hero who anchors all three. Before spending duplicates or ability-upgrade resources, write down which heroes appear in every rotation and start there.

A practical order based on the confirmed role list: prioritise the Collector role first, because the game's core loop is a bomber squadron gathering resources and hunting rare items, and resource income compounds into every other upgrade. Attackers come second since destroying rocks gates progress through stages. Support and Specialist heroes depend on their specific abilities, which the sources do not itemise, so evaluate them by reading in-game tooltips rather than by role label alone.

• Step 1: List all heroes in your three team rotations and mark the ones that appear in every rotation.
• Step 2: Among those, invest in Collectors first (resource income), then Attackers (rock-clearing speed).
• Step 3: Push a small number of abilities toward level 10 rather than spreading upgrades across all 20.
• Step 4: Only fuse duplicate heroes or items after confirming the copy you keep has the better attribute roll.

Where Star Investment Fits: Skill Tree and Steam Market Unlock

Stars and gear upgrades are not the only progression lanes. The Steam store page describes a massive skill tree inspired by Path of Exile, with dozens of nodes that apply upgrades and unlocks to your entire team. Because tree nodes affect every hero at once, they are usually a better early investment than starring a single hero, whose bonus only applies when that hero is on the active rotation.

The other system that interacts with duplicates is the Steam Market. Bomb Farm supports trading items with other players on the Steam Market, and the community Trading sub-forum is active. Multiple independent Steam Community threads ('market requirement change again', 'Did the Market requirement change to 5-19 Normal?', and 'Activating the market function (5-19)') confirm that Market access is gated behind a progression requirement that Stream On has already changed at least once. The current requirement is reported by players as clearing stage 5-19 on Normal, but this is a player report, not an official statement.

This matters for star planning because once the Market unlocks, a duplicate is no longer only fusion fodder. A tradable duplicate with a good attribute roll may be worth more sold than fused, while cheap duplicates bought from other players can accelerate stars on the hero or item you care about. Do not fuse rare duplicates blindly before you reach the Market gate.

• Skill tree: dozens of Path of Exile-style nodes, team-wide effect, confirmed by the Steam store page.
• Steam Market trading: confirmed by the store page and an active Trading sub-forum.
• Market gate: reported as 5-19 Normal by players; requirement has been changed by the developer at least once.
• VIP Pass holders reported a 'VIP Pass Market Lock Bug' after an update, so a locked Market is not always a progression issue.

Community Tips and Known Issues Around Progression

Several Steam Community threads mention a friend code system that grants free loot when you enter another player's code. Free loot means extra reveals, which in turn means more duplicates to fuse, so entering codes is one of the few zero-cost ways to speed up star progress in the current version. The threads all come from the same forum, so treat the exact rewards as unconfirmed.

Players have also asked how to re-enable the auto map advance feature after turning it off. Since stars and upgrades only matter if your squadron is actually progressing through stages, make sure auto advance is on when you are pushing toward the Market requirement. Finally, be aware that the community contains multiple threads disputing VIP Pass refunds and account actions; the paid VIP Pass exists, but weigh those reports before spending money purely to accelerate star or gem farming.

If you discover the actual gem list, ritual costs, or star multiplier values in-game, the Steam Community Guides section for AppID 4892010 is the best place to publish them so that other bombfarm wiki readers can verify against a second source.

• Friend codes: enter other players' codes for free loot (multiple community threads, single source type).
• Auto map advance: can be disabled; players have asked how to turn it back on.
• VIP Pass: paid item exists; refund disputes and a Market lock bug have been reported.
• Free to play, Windows only, with Steam Achievements, Steam Cloud, and Family Sharing.