エメラルド

A dual-purpose gem built around Poison and Regeneration.

• Weapon socket: Chance on hit to apply Poison (Chipped: 35% / 1 Poison).
• Armor socket: Grants Poison resistance (Chipped: 10% resistance).
• Backpack slot: After a delay, grants Regeneration (Chipped: 1 Regen after 3s).

• Poison is a stacking DoT debuff. While applied, it deals damage equal to the stack count at a fixed tick rate (~1 second), dropping by 1 stack each tick. Ten stacks thus deal 55 total damage across 10 ticks (10 + 9 + ... + 1) — a triangular-number scaling.
• Emerald's weapon proc rate caps at 80% starting from Flawed. What scales at Perfect is the amount of Poison applied per trigger (1 → 2 → 4), which drives a massive effective DPS increase at Perfect.
• Poison resistance is a damage-reduction multiplier on incoming Poison damage, not a stack-blocking effect. You begin to meaningfully survive Reapers at Regular (20%) and up.
• Backpack Regen triggers once per battle after its timer, similar to Ruby's backpack effect. Unlike Ruby and Sapphire, however, multiple backpack Emeralds each fire independently and their Regen sums up.
• 1 Regen stack heals 1 HP every 0.66 seconds, consuming 1 stack each tick. 7 Regen thus heals 7 HP over roughly 4.6 seconds.
• Poison can be wiped by buff-removal or cleanse effects, but because it is applied on hit, damage already dealt prior to cleanse is not refunded.

Emerald covers both offense (Poison) and defense (Regen + Poison resistance), making it a flexible "continuous damage" gem. Its strength isn't burst damage but rather grinding the opponent down over time.

Weapon-socket Emerald is best paired with fast multi-hit weapons (Shortbow, Critwood Staff, Falcon Blade) to rack up Poison stacks rapidly. Perfect Emerald's "80% / 4 Poison" averages 3.2 stacks per hit, which can exceed 60 stacks within 20 seconds. Triangular-number scaling then pushes total Poison damage into the 1000+ range, enough to outlast even high-HP enemies.

The Regen from backpack Emerald fuels Thornbloom (Regen → lifesteal + thorns) extremely well, making it the centerpiece of Adventurer's dual-defense-offense build. Three Perfect Emeralds in the pack grant 21 Regen at 3 seconds, which Thornbloom then converts into lifesteal and reflect damage en masse.

Armor-socket Poison resistance is a meta pick against Reaper. At Perfect (40%), it effectively counters full-stack Poison weapons. But because it occupies an armor socket, it only earns its slot in an anti-Poison meta; otherwise Ruby or Topaz typically wins.

Among the five gems, Emerald is "more build-restricted than Ruby or Sapphire, but maxes out higher when it hits." Outside Reaper and Adventurer, adoption priority is moderate.

• Socket into Reaper poison weapons (Belladonna's Whisper, Death Scythe) to maximize Poison stacking. Flawless+ unlocks 2-4 Poison per hit, accelerating accumulation.
• On Adventurer, stack three to four copies in the backpack to fuel Thornbloom's Regen conversion into lifesteal + thorns.
• Armor socket at Regular (20%) or higher is the standard Reaper counter. Priority rises sharply in a poison-heavy meta.
• Chipped Emerald (35% / 1 Poison) is weak; skip past Chipped by crafting, and push Flawed all the way to Perfect on a direct upgrade path.
• Healing Herb and Balance Wand Regen layering makes Emerald viable as a healing base outside Adventurer.
• Poison ignores Amethyst's buff removal, but some cleanse/purify effects can remove it. Scout the opponent before committing.

Reaper Full Poison

Dual-wield Belladonna's Whisper x2 or Death Scythe x2. Socket Perfect Emerald in one weapon and Flawless Emerald in the other to maximize Poison per hit. Pestilence Flask extends the Poison ceiling, Fly Amanita adds passive stacks, and by 20 seconds you can exceed 100 stacks. Place Death Scythe adjacent to double Poison damage, and the triangular scaling produces 3000+ total Poison damage in a single match.

Adventurer Regen Conversion

Line up four Chipped-to-Regular Emeralds in the backpack, opening with 12-20 total Regen at 3-4 seconds. Thornbloom converts each Regen into lifesteal + thorns, building offense and defense simultaneously. Extend the thorns synergy via relic access (Thorn Crown etc.) and use reflect damage to reduce the opponent's effective attack count.

Pyromancer DoT Hybrid

Apply Heat via Flame Whip or Quinta Prinis, and socket Perfect Emerald into a secondary weapon for Poison application. Heat + Poison stack independently, so damage scales exponentially with time. Add Frozen Flame for Cold and you get a triple-DoT build.

• Poison is cumulative, so fast-finish matches don't reward it. For burst-oriented openings, other gems are preferable.
• Backpack Regen stacks across multiple copies, but the "once per match" trigger still applies. Don't expect continuous late-game output.
• Poison resistance reduces incoming Poison damage but does not block stacks from being applied. Even at 100% resistance, stacks still build up if not cleansed.
• Chipped Emerald is weak (35% / 1 Poison). It is inferior to early Ruby/Sapphire unless you are committing to the craft path.
• Armor Poison resistance is dead against non-Reaper opponents. Be ready to swap to another gem depending on meta reads.
• Poison does not bypass Block. Against Block/Shield-heavy opponents, non-Poison damage stalls while Poison tries to finish the job.

This item feeds into the following upgrade paths.