Silver Palace — Hotel Catalysts Guide

Hilbert's Hotel Catalysts (or Hotel Catalysts) represent the primary combat-draft mechanic in Hilbert's Hotel. Every time you clear a combat chamber or visit the mid-run Supplies Shop, you draft or buy these reagents using Hilbert's Hotel Vouchers.

There are 166 Hotel Catalysts in total, each themed around real-world alchemical minerals, salts, and metallic transmutations. Unlike static stat sticks, Catalysts interact directly with combat mechanics - transforming skill rotations, eliminating resource costs, or unleashing screen-wide elemental reactions.

Every Hotel Catalyst operates along a strict 3-tier evolutionary chain:

• Base Catalysts (59 Total): Your starting draft pool. Most Base Catalysts begin at Lv. 1 and can be leveled up to Lv. 3 via Reshape to scale their base percentages (e.g., Fuming Sulphur grants a 20% hit chance to detonate 3 Burning Sparks for 180% AoE Ignis DMG; Raw Mercury grants a 5% hit chance to restore 20% Max HP).
• Refined Catalysts (50 Total): Instead of an ordinary 'Level 4', a Base Catalyst undergoes Reform to transform into an evolved Refined Catalyst with a new name and heightened triggers (e.g., Fuming Sulphur evolves into Molten Sulphur, doubling the proc chance from 20% to 40%; Immaculate Gold evolves into Wrought Gold).
• Synthesis Catalysts (57 Total): The pinnacle buffs of Hilbert's Hotel. Forged automatically when you assemble two specific Refined Catalysts from different alchemical chains (e.g., combining Molten Sulphur + Fulgurite Copper creates Calcined Copper, which preserves both parent effects while unlocking an explosive cross-trigger synergy).
• Storage Pool Expansions (+4 Catalysts): Unlocking Storage Upgrade I & II in the Membership Privileges tree permanently introduces Corrosive Salt, Plagioclase Crystal, Phantom Quartz, and Black Agate into your draft pool.

Upgrades are handled at the Supplies Shop or via rest doors through two distinct systems:

Reshape (Level Scaling)

Spends Hotel Vouchers to advance a Base Catalyst from Lv. 1 to Lv. 3. Each level amplifies base damage multipliers, trigger chances, or recovery ceilings without altering the fundamental mechanic.

Reform (Evolution)

Transmutes a max-level Base Catalyst into its Refined counterpart. This completely alters the card art, elevates the perk tier, and qualifies the stone for Synthesis forging.

Always check the binding tag on a Catalyst card before drafting it:

• Universal / No Binding (77 Catalysts): Can be triggered by any teammate via universal combat actions like Critical Hits, Parries, Executions, or Tactical Assaults.
• Reactor Attribute Bound (20 Catalysts): Locked to one of the elemental Reactor Attributes (Ignis, Glacies, Fulmen, Gravitas, Radiatio, or Alba). Only draft the attribute(s) your current squad uses.
• Character-Bound (69 Catalysts): Only work for one specific character on your team and do nothing for the other three. In exchange, they completely overhaul how that character plays:
• Red Rose: Cuts Ultimate DMG by 50%, boosts Skill DMG by +225%, and lets her generate and spend Rose Petals to deal 40% of her Max HP as bonus DMG.
• Argos: Cuts Ultimate DMG by 50%, boosts Charged Attack DMG by +400%, and unlocks a 2nd and 3rd stage on his Charged Attacks.
• Ashley ("Cinderella"): Increases Ultimate Charge Efficiency by +225%, Ultimate DMG by +225%, and Ultimate Speed by +100%.

Follow these 3 tactical drafting directives to guarantee consistent 12-floor clears:

• 1. Lock in a Synthesis Pair Early: Scout your first two combat drafts for Base Catalysts that share a known Synthesis recipe. Dedicate all early Vouchers to Reshaping and Reforming those specific stones.
• 2. Prioritize Your On-Field Carry: Because your active carry accounts for ~80% of damage and screen time, draft Character-Bound Catalysts for your lead carry before drafting off-field utility.
• 3. Pass on Unmatched Attributes: Never take an Attribute-Bound Catalyst unless your primary carry or high-frequency Tactical off-fielder matches that exact element.