Final Swarm chest EV vs Skill Tree — when to bank into Mythicals

The chest EV math and the Skill Tree priority order are the two sides of the Keys economy. This article walks through the chest EV table, the Skill Tree vs chest decision rule, and when the Mythical chest becomes the right choice over a Skill Tree rank.

Chest EV table

The Mythical tier was added on 2026-07-27 with the Mythicals✨ update and is the top-rarity chest in the game. The expected Keys per opened chest tier is a player-entered scenario in the Skill Tree optimizer; every calculator field is editable so you can stress-test against your own observed drop rates.

The decision rule

The optimizer implements the spec’s decision rule:

1. If rank[Damage] < 5, bank into the Skill Tree regardless of chest EV. Damage ranks compound across runs and the marginal return is materially higher than any chest.
2. Otherwise, compare the next Skill Tree rank’s projected Keys-equivalent against the highest chest EV. Bank into the higher of the two.
3. If you have hit the cap on every Skill Tree node, route every Key into Mythical chests. There is no permanent progression left to buy.

The Skill Tree’s compounded return across future runs is the load-bearing math. A Damage rank on the Skill Tree applies to every run that follows the unlock; a chest roll is a one-shot spike.

When Mythical chests beat the Skill Tree

The Mythical chest becomes the right choice in three scenarios:

• Every Skill Tree node is at cap (rank 50). There is no permanent progression left to buy; the only remaining decision is whether to chase a Mythical-tier Jungle weapon via chest rolls.
• The next Skill Tree rank’s projected Keys-equivalent is below the Mythical chest EV (~480 Keys). This happens for low-priority nodes once the priority nodes are banked.
• You are deliberately farming the Mythical chest drop for the Mythical-tier Jungle weapon. Mythical is the only chest tier that can drop a Mythical-rarity weapon.

When the Skill Tree beats chests

The Skill Tree is the right choice in three scenarios:

• rank[Damage] < 5. Bank into Damage until rank 5 regardless of chest EV.
• You have hit the Wave 8 boss wall. Bank Max Health and Defense ranks before opening more chests; the Wave 8 inflection is the load-bearing skill gate.
• You are chasing the per-run upgrade rotation rather than the chest tier. The Holy Trinity (Multi-Shot + Attack Speed + Projectile Count) compounds multiplicatively on top of Skill Tree Damage ranks.

Why the chest EV numbers are guidance-grade

Evolution Studio Games does not publish per-tier drop rates. The chest EV numbers above are taken from the optimizer spec and are treated as player-entered scenarios in the calculator. The numbers are a useful planning baseline but should be verified against your own observed drop rates — Evolution Studio Games may rotate per-tier drop rates between patches without notice.

How to use the chest EV math

1. Open the Skill Tree and Key Spending Optimizer.
2. Enter your current Keys balance and your current rank on each node.
3. Set the chest EV overrides to match your own observed drop rates (the calculator accepts player-entered overrides).
4. The optimizer returns the next-best spend and the full progression path.

Sources and verification

The chest EV numbers are sourced from the optimizer spec and treated as player-entered scenarios. The chest tier ladder and the Mythicals✨ chest rarity are sourced from the official Roblox game page, Rolimons, and Earnaldo. The VIP +30% Keys multiplier is sourced from the live Roblox game-passes API and Earnaldo’s monetization guide. All claims on this page were last verified on 2026-08-01.