Lost Ark: Ark Grid, the complete guide to Cores and Astrogems at ilvl 1700+ (August 2026)

The Ark Grid is the power tier that separates a character who just hit 1,700 from one that's actually competitive in raids, and it's also the one that most players leave neglected. Yet it has been in the game since the Day of Prophecy update on November 19, 2025, and everything added since then feeds into it.

There are two reasons to get to it now. The server merges on August 26 and September 2 will concentrate populations and make the raids that drop Cores easier to fill. And the official Q3 roadmap specifies that the Warpweaver, coming in September, "starts with 6 Relic Cores": her grid will already be filled in, the only limiting factor will be your stock of Astrogems. Gems accumulated in August will therefore be put to direct use come the fall.

Why all the labels in this guide are in English

Amazon Games removed the French and German localizations of Lost Ark starting with the May 2025 monthly update: language options pulled from both the settings and the official channels, the client switched to English by default, AZERTY and QWERTZ keyboard layouts removed shortly after.

Direct consequence: there is no official French label for the Ark Grid. The French terms still in circulation (Portes du Chaos, Raids du gardien, Donjon des abysses, Forteresse) come from the pre-May 2025 client and remain correct for older content; for all of Tier 4, we stick with English.

Six slots, two families

The Ark Grid is character-specific, not roster-wide. It activates as soon as you equip your first Core, then one additional slot unlocks with each weekly reset, up to six. A character freshly leveled to 1,700 will therefore take several weeks to open up their full grid: equip them with a first Core as early as possible, even without gems behind it. The six slots are split into two families of three:

• Order of the Sun — the Core that defines the build. It can change how a skill functions or transform the rotation via the Destiny effect.
• Order of the Moon — it sets the trigger condition for that Destiny effect: using a certain number of skills, a specific skill, etc.
• Order of the Star — it rounds out the set with supplementary effects: attack speed, cooldown reduction.
• Chaos of the Sun, Chaos of the Moon, Chaos of the Star — three generic Cores, identical for every class, that simply increase your damage or your support output.

Each class has three options per slot, for a total of 36 potential Cores. But Order Cores work in matched sets: you don't mix Cores designed for two different builds, a Reflux Core with an Igniter Core for instance. Choosing your build before investing isn't optional, it's a prerequisite.

Where Cores drop, and how to force the one you need

Four types of content bring Cores down: Kazeros Raid: Armoche (Act 4), Kazeros Raid: Denouement, the Shadow Raid: Serca and the abyssal dungeon Horizon Cathedral. The latter is by far the most accessible: opening on June 17, 2026, designed for four players, it features three floors requiring 1,700, 1,720 and 1,750 item level, and hands out Graced Shards on top, which can be exchanged for Core and Astrogem chests.

Rarities range from Epic to Ancient, with Hard mode significantly increasing the odds of high rarity. Above all, never sell off a duplicate: registering a Core grants Core Essence, and 200 Core Essence buys a selection chest of your choice, Relic or Ancient. This is the true pity system of the Ark Grid.

At 200 Core Essence per chest, a chosen Core is worth four Ancient Cores or about fifteen Relic Cores: Epic duplicates only help round things off, it's the Relic and Ancient Cores useless to your build that really push the counter forward.

Astrogems: six variants, one Willpower budget

A Core on its own produces no effect. It must be activated with Astrogems, up to four per slot. Each gem contributes points to the Core and consumes Willpower, which the Core provides in a limited amount depending on its rarity:

• Epic Core: 9 Willpower, a single effect tier, at 10 points.
• Legendary Core: 12 Willpower, effects at 10 and 14 points.
• Relic Core: 15 Willpower, effects at 10, 14, 17, 18, 19 and 20 points.
• Ancient Core: 17 Willpower, same tiers, but the effect at 17 points is much stronger than its Relic version.

The tiers that matter are 10, 14 and 17. The 18, 19 and 20 tiers only bring a marginal gain, comparable to raising Karma beyond level 21: don't sacrifice anything to reach them. Gems can be freely moved from one slot to another: nothing is final. The theoretical cap, with a cost-reduction node at level 5 everywhere, allows 8+8+9+10 on a Relic Core and 8+9+10+10 on an Ancient Core.

Order Astrogems can only be placed around Order Cores, Chaos ones around Chaos Cores. Each family has three variants, differentiated by their cost:

The side effects scale up to level 120: at that cap, Maxroll reports +4.4% attack power, +9.7% Additional Damage or +10% boss damage depending on the line. That's the dessert: activating Cores comes before optimizing side nodes.

Processing: 900 gold per attempt, with no turning back

A raw Astrogem (Uncommon, Rare or Epic) must go through a processing mini-game before it can be equipped. Four diamonds progress there from level 1 to level 5:

• Red, top: the Willpower cost reduction, a decisive diamond as long as your Cores aren't activated.
• Yellow, bottom: the points contributed to the Core, and therefore access to tiers 10, 14, and 17.
• Green and blue, on the sides: the additional combat effects.

Each round, the game offers four options and draws one at random: a bonus of +1 to +4 on a diamond, no change, a −1 penalty, a change in the gold cost of the remaining attempts (−900 or +900), a replacement of the green or blue effect, or one to two extra rerolls. The number of attempts depends on the starting rarity: 5 for an Uncommon, 7 for a Rare, 9 for an Epic, at 900 gold per unit in all cases. An Astrogem Processing Reset Ticket costing 100 Blue Crystals allows you to restore a gem, only once.

At the end, the gem takes on a rarity determined by the total of the four diamonds: Legendary from 4 to 15 combined levels, Relic from 16 to 18, Ancient from 19 upward. This final rarity grants no additional bonus, it only serves as raw material for fusion. Hence the most counterintuitive rule of the system: always finish a failed processing run. A mediocre Relic is still an excellent material; a gem abandoned halfway through is worthless.

Fusion, the tool everyone underestimates

Three Astrogems fused for 500 gold produce a new one. On raw gems, each material weighs equally on the type of the result: two Corrosion and one Stability give a two-out-of-three chance of getting a Corrosion. The result comes out Uncommon 52% of the time, Rare 44% of the time, and Epic 4% of the time, with a one-in-two chance of being roster-bound rather than character-bound. This is the only existing transfer mechanic: Astrogems never go through the auction house, and the end-of-August server merge won't change that.

On already processed gems, the logic is different: the game distributes a total of points based on the rarity of the result, i.e. 4 to 15 for a Legendary, 16 to 18 for a Relic, 19 or 20 for an Ancient. Fusing three Legendaries therefore has almost no chance of producing something usable. Reserve this move for Relics whose stat distribution doesn't suit you.

Practical corollary: don't invest gold in processing Immutability and Destruction gems early on. Their floor cost is 5 Willpower, a threshold you'll reach elsewhere anyway. Keep them as fusion materials, at a 2:1 ratio with Stability or Corrosion gems.

The weekly farming plan

Raw Astrogems come from four sources, all compatible with a normal routine:

• The Kurzan Front, guardian raids, and Chaos Gates from 1,700 ilvl upward.
• A dedicated NPC, in exchange for gold then for honing materials, each currency having its own weekly limit. The Uncommon-Epic chest is bought with character-bound gold: don't dip into your tradable gold.
• Exchanging for Astrogem Shards, obtained by dismantling gems you won't use.
• Paradise rewards, including those from the current Season 4.

Underused roster trick: characters between 1,700 and 1,720 ilvl already have access to these sources. They're your gem farms, and since fusion offers a fifty-fifty chance to bind the result to the roster, their output eventually makes its way to your main.

What to do this week

Since processing never comes out perfect, the priority order is simple: aim for 10 points on each Core, then 14, and only push toward 17 once all six slots are active. A character with six Cores at 10 points beats a character with one Core at 17 points and five inactive slots by a wide margin.

Three milestones will shape the end of summer: the Kazeros Act 2 Extreme raid, announced for August on the official roadmap, server merges on August 26 and September 2, and then in September the Warpweaver and the Base Camp system, which will bring new and returning players straight to 1,700 with pre-honed gear, right at the entry point to the Ark Grid.

The routine to stick to fits in four lines: use up your weekly Astrogem purchase limits, register all duplicate Cores to raise Core Essence toward the 200 chest, clear Horizon Cathedral floor 1 on every eligible character, and save your Immutability and Destruction stones for fusion instead of processing them. The rest is a matter of patience: the Ark Grid isn't something you sprint through, it's a system that rewards consistency over several months above all else.