革のカバン

• Passive: backpack slots +3
• No additional effect

Backpack Battles is designed so total bag slots directly determine combat power, and slot expansion is the prerequisite for every build. Leather Bag produces 0.75 slots per gold — among the most efficient Common-rarity bags. However, compared to Mage-only Puzzlebag of Love (5G, +4 slots + healing +20% + max HP +7), for Mage specifically it's a downgrade.

Leather Bag is a Neutral bag delivering a pure +3 slots at 4G and 2x2 — the standard early slot expansion for the six classes outside Mage (Ranger / Reaper / Berserker / Pyromancer / Adventurer / Engineer). With no additional effect, it's a purely slot-count-increasing design, but precisely because of that it provides constant value regardless of class or build. It appears in every class's starter preset, acting as an effective build foundation from early to mid game.

The importance of slot expansion is rooted in Backpack Battles' combat design. More empty slots = more equipped items = cumulative growth in damage / defense / healing / utility across all axes. For example, expanding from the starting 10 slots to 13 via one Leather Bag, and filling the 3 new slots with weapons or synergy items at "1G per 1 damage" efficiency, a 100-300+ net damage increase per battle is expected. That's outstanding ROI on 4G.

Comparing within the Mage lane: Puzzlebag of Love (5G) costs just 1G more but adds +4 slots + healing +20% + max HP +7 as a triple-effect bag, so Mage should prioritize Puzzlebag of Love over Leather Bag. Conversely, for the six non-Mage classes, Leather Bag is the optimal Common-tier bag choice — secure 1-2 without hesitation, as the default play.

It also functions as a crafting material for upper bags like Duffle Bag / Holdall, but because Leather Bag's own cost efficiency is solid, many cases keep it uncrafted through late game. Multi-stacking is also valid: 2 copies = +6 slots, 3 copies = +9 slots for rapid bag-capacity expansion. Since 2x2 takes space, placement planning matters when stacking bags.

• Early buy candidate for all classes except Mage. 4G for pure +3 slots
• Piggy Bank (economy) → Leather Bag (capacity) → key-item buys creates a virtuous cycle
• Note the bag itself consumes 2x2 = 4 cells. Think in net (differential) terms
• Secure as crafting material for upper bags (Duffle Bag / Holdall)
• Multi-stack (x2-3) for major bag expansion. Handles mid-game-onward gear counts
• On Mage, prioritize Puzzlebag of Love (5G) over Leather Bag. +1G buys the triple-effect upper
• Even with poor early shop RNG, Leather Bag frees up item capacity and widens mid-game pick breadth
• 1-2 copies is nearly sufficient. Compare against other key items before buying a third

All Classes (ex-Mage) Early Slot Expansion

Secure 1 Leather Bag on rounds 1-2, expanding early equipment count to around 13 — the basic template. Fill added slots with weapons / accessories / foods to solidify the build foundation. Consider a second copy from mid game.

Pyromancer Flame Mass-Stack

Leather Bag x2 + Flame x8-10 + Double Axe fills +6-8 expansion slots entirely with Flame. Maximizes total bag Heat supply and chains Heat-threshold trigger items' consecutive activations.

Engineer Battery Mass-Stack

Leather Bag x2 + Battery x6-8 + Engineer weapons secures use-speed +60-80%. A rapid-attack build overwhelming with tempo, where Leather Bag's capacity expansion is the mandatory foundation.

Adventurer Mass Item-Activation

Leather Bag x2 + Twine Thread x2 + 5 foods + 3 pets maximizes total bag item activations. Twine Thread max HP growth and heal / damage all lift together — a multi-gear build.

• Pure slot expansion without added effects. Zero direct combat contribution
• Occupies 2x2 = 4 cells; net addition is only 3 slots. Placement planning is important
• For Mage, Puzzlebag of Love (5G, +4 slots + triple effect) is a strict upgrade. Leather Bag not recommended
• Multi-stacking is linear; no acceleration. 2-3 copies is the realistic cap
• Crafting to upper bag (Duffle Bag etc.) consumes the material. Time the craft
• More slots without drawing good items doesn't translate to combat power. Balance against shop RNG
• Its own size may crowd the bag-center weapon area. Mind corner / edge placement
• Over-buying bags early leaves insufficient funds for key items (weapons / key accessories)

This item feeds into the following upgrade paths.