Equipment Forging & Upgrade Guide

Forging and upgrading equipment is the primary way to increase your squadron's Combat Power in Bomb Farm. This guide covers the full enhancement pipeline — from opening your first chest to pushing endgame gear — and helps you spend resources efficiently at every progression stage.

How Forging Works

Forging applies a +N enhancement level to any piece of equipment, directly increasing its stats. You access the forge through the Forging & Fusion menu, select an item from your backpack, and spend gold to attempt an upgrade. Each successful forge raises the item by one level, indicated by the +N suffix next to its name.

A critical detail for new players: forging up to +8 has a 100% success rate and will never fail. This makes early forging an extremely safe and efficient investment. Beyond +8, each subsequent level carries an increasing chance of failure, so you should plan your gold reserves carefully before attempting higher enhancements.

Because only destroying minerals produces gold and there is no passive income, every coin you spend on forging must be earned through active play. Prioritize forging your best-rarity items first and avoid spreading upgrades thinly across gear you plan to replace.

Equipment Rarity Tiers

Bomb Farm features six rarity tiers, ranging from Common at the lowest end up to Mythical at the highest. Rarity directly determines how many stat properties a piece of equipment can roll — higher-rarity items simply have more attribute lines, making them stronger even before any forging is applied. With 240 total equipment pieces in the game, each tier offers meaningful upgrades as you progress through the 600 stages.

Items are obtained primarily through chests, which drop when your heroes destroy minerals on the battlefield. Opening a chest can yield equipment, heroes, gems, time parts, or keys. When you open a piece of gear that has higher Combat Power than what you currently have equipped, swap it in immediately — Combat Power is the universal benchmark for measuring strength.

As you reach higher difficulties, the chests you earn will increasingly contain rarer equipment. Holding onto lower-rarity items is unnecessary once you have superior replacements; excess gear can be fed into the fusion system or sold on the Steam Market to other players.

Fusion System

Fusion is the companion system to forging and allows you to combine duplicate or unwanted items into stronger results. The fusion menu lets you select multiple pieces of equipment and merge them, producing an item of higher rarity or improved stats. This gives every drop value — nothing you pull from a chest is truly wasted.

Hero fusion works on a similar principle: duplicate heroes can be fused together to create a hero of higher rarity. Since rarity determines how many skills a hero can learn, fusing duplicates is one of the most impactful upgrades available. Always check whether a duplicate hero is worth more as fusion material or as an additional battlefield slot before committing.

Best-in-Slot Recommendations by Stage

During the early game (roughly the first set of stages on Normal difficulty), focus on equipping whatever has the highest Combat Power and forging it to +8 immediately. Since these upgrades cannot fail, they represent free stats. Spend gold liberally on the talent tree's first tiers and on forging — hoarding currency provides zero benefit in Bomb Farm.

In the mid-game, as you push through higher difficulties and begin accumulating rarer drops, shift your focus toward consolidating your best items through fusion. Equip the highest-rarity gear across all active heroes and only forge items you intend to keep long-term. This is also when you should begin investing gems into Star ratings, which provide stat multipliers to heroes and compound the value of well-forged equipment.

For endgame progression approaching stage 600 and the hardest difficulty tier, target Mythical-rarity equipment across all slots and push forge levels well beyond +8. At this stage the risk of forge failure is significant, so stockpile gold from replaying earlier stages — revisiting cleared maps yields full rewards with no penalty. Pair maxed gear with a fully developed talent tree and high Star ratings to maximize your Combat Power for the global leaderboards.

Tips and Common Mistakes

Never let gold sit idle. Unlike many idle games, Bomb Farm produces no passive income — your heroes must be on the field breaking minerals to earn anything. Every coin should go toward forging, talents, or other upgrades the moment you have enough for a meaningful purchase.

Keep your backpack managed. If your inventory fills up, newly dropped items from minerals will be lost. Regularly fuse or sell surplus equipment to maintain open slots. Items and heroes can also be listed on the Steam Market for real trading with other players, turning your excess into someone else's upgrade.

Finally, remember that keys only drop from non-boss stages (outside of X-10 levels), and you need them to pass through timed stage gates. Do not waste keys recklessly — running out means your progression stalls entirely until you farm more from earlier levels.