[Question] Using unused difficulty flags (10H/25H) to create custom Heroic modes in WotLK raids that don't support them

Custom Code and Mods
1

Hello everyone,

I’m currently exploring the feasibility of a small content extension project for Wrath of the Lich King, and I’d like to know if anyone has already done something similar, or whether this idea has been discussed before.

:bullseye: Goal

The idea is to reuse the Heroic difficulty flags already present in the game client (RAID_DIFFICULTY_10MAN_HEROIC, RAID_DIFFICULTY_25MAN_HEROIC) and apply them to older WotLK raids that do not normally use them, in order to create custom high-difficulty variants.

There would be no modification to the boss AI or hardmode scripting. The method would rely solely on:

  • Duplicating creature entries with increased HP/damage
  • Using spawnmask = 2 to link them to the Heroic difficulty
  • Setting up separate loot tables for the Heroic variant
  • Optionally applying a passive, undispellable aura on players when entering the instance (e.g., +30% damage taken)
  • No .cpp script modification of the boss behaviors

:brick: Affected raids

Here is the list of WotLK raids that do not use the Heroic difficulty flags, making them excellent candidates for this system:

Raid Native difficulties Uses 10H/25H flag?
Naxxramas 10 / 25 :cross_mark: No
Eye of Eternity (Malygos) 10 / 25 :cross_mark: No
Obsidian Sanctum (Sartharion) 10 / 25 :cross_mark: No (HM via drakes)
Ulduar 10 / 25 + internal HMs :cross_mark: No (HM via mechanics)
Onyxia’s Lair (WotLK version) 10 / 25 :cross_mark: No

:puzzle_piece: Special note:

In the case of Ulduar and Sartharion, enabling 10H/25H modes would effectively create two additional difficulty layers:

  • For Ulduar: Normal + Heroic, each with/without hard mode triggers
  • For Sartharion: Normal + Heroic, each with 0–3 drakes

That’s four total combinations per raid, without touching scripted logic.

:gem_stone: Custom loot philosophy

To motivate players without breaking class balance or progression:

  • Rewards could be purely cosmetic (old armor/weapon models)
  • Or offer ilvl 284 items (same as ICC loot) that are:
    • Very narrowly specialized (per spec or mechanic)
    • Designed for lateral progression, not raw power creep
    • Based on legendary weapon models from previous expansions (e.g., Sulfuras, Warglaives) or restored Tier 3/Naxx40 skins

The goal: offer a stylized, rewarding challenge for experienced players without power-skipping the main WotLK content.

:red_question_mark: My questions

  • Has this idea been implemented or discussed in the context of TrinityCore or AzerothCore?
  • Is the engine’s handling of spawnmask, difficulty flags, and loot table segregation reliable and flexible enough to support this without editing core C++ code?
  • Are there any known technical caveats (AI, phasing, aggro bugs) to this approach?
  • Are there tools or SQL scripts to duplicate a raid cleanly and associate it with a different difficulty flag?

:folded_hands: Thanks in advance

I’m not actively developing this yet — just gathering feedback and insight before investing time.

Best regards,

(This post was translated from French with the help of ChatGPT.)

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