One-Armed Bandit Raid Guide in Liberation of Undermine
On this page you will find both a short and full written guide for the One-Armed Bandit encounter in the Liberation of Undermine raid. Read on to learn everything you need to know to take on One-Armed Bandit.
One Armed Bandit Raid Guide
Quick TLDR Guide
Core Mechanics:
- Avoid the Coins rolling across the room.
- If you stand next to the coin as its rolling past you, you gain a damage and healing buff.
- Once coins land on the floor use the extra action button to roll it again. The boss gains a damage buff for each coin on the floor (and not rolling).
- Tanks: Run away with
The Big Hit (as it is casting) and place the
Shocking Field away to the sides or entrance.
- Healers:
Foul Exhaust applies a raid wide healing absorb which deals damage over time. Heal to remove the absorb and damage.
100 Energy - Add Phase:
- Interrupt
Overload! on the Reel Attendants.
- Kill the Reel Attendants ASAP as they deal raid wide damage.
- Each Reel Attendant will drop a coin on the floor, use your extra action button on the boss to deposit the coin. You have 30 seconds from them spawning to deposit the coin before you wipe.
- Each coin deposit must be a unique combination (e.g. You cannot do Coin & Shock twice).
- The combination of coins you deposit adds a new mechanic for the next boss phase.
- Once all 6 combinations have occurred the boss will enter the enrage phase.
- Run away from the raid if you have
Withering Flames. Fire tornadoes will spawn after getting dispelled.
- Healers: Dispel
Withering Flames once the player has moved away from the raid.
Enrage Phase:
- Avoid the
Voltaic Streak beams.
- Tanks: Keep the boss towards the edge of the room to make beam dodging easier.
- Players with
Hot Hot Heat will fire beams towards the boss from their location.
Strategy Guide: Full Guide
Core Mechanics:
Pay-Line will fire a giant casino chip across the room. If you get hit by this you will be stunned. If you stand next to it as it is rolling across the room you will gain
High Roller! which increases your damage, healing and movement speed!
- Once a
Pay-Line chip reaches the wall it will fall to the floor and deal damage to all players (increased damage to those within 15 yards) and the boss will gain a stack of
Up the Ante. You can move next to the coin to kick the coin across the room again which removes the buff from the boss and gives you more chances to get or maintain
High Roller!.

- Tanks: The tank swap of this fight is
The Big Hit. The boss will start to cast this on you and during this time you need to run away and find a good place to drop the
Shocking Field that spawns afterwards. This leaves a pool on the ground which can only be removed by using coil mechanics. Ideally you want to place these away to the sides or entrance to avoid needing to activate coils later on in the fight.

- Healers:
Foul Exhaust will apply a raid wide healing absorb. Every second this healing absorb is on the player it will deal damage over time and apply a stacking movement speed reduction. Be ready with burst healing to remove this before people really need healing!
100 Energy - Add Phase:
In this phase 3 Reel Attendants will spawn in set locations. They will have icons above their head and are also named with the coin they hold. Defeat them to make them drop their coin and deposit 2 coins to end this phase. The coins deposited must be a unique combination each time.
You are able to see which combinations you have not deposited at the back of the room:
- Reel Attendant Mechanics:
Overload!: Deals raid wide damage and can be interrupted.
Electric Blast: Deals a moderate amount of damage to their target and applies a small stacking raid wide DoT.
Withering Flames: This debuff deals ticking damage to the player and reduces your max health. This player needs to run away from the raid and be dispelled. After being dispelled fire tornadoes will appear from their location.
- Kill the Reel Attendants ASAP and deposit your desired coin combination. The following order of coins worked well during testing this boss
and this will be updated after the raid goes live.
- 1. Flame & Coin
- 2. Coin & Bomb
- 3. Shock & Flame
- 4. Shock & Bomb
- 5. Flame & Bomb
- 6. Coin & Shock
- To pick up the coin you simply run over it. You will then be given an extra action button. Get in melee range of the boss and use it to deposit the coin.
- Failing to deposit the coins in time, or depositing the same combination twice will result in the boss becoming enraged and the raid dying shortly after.
- The combination of coins you deposit adds a new mechanic for the next boss phase, a full list of what they do can be found in the table below.
Coins Deposited | Effect | Additional Mechanics |
---|---|---|
Shock and Flame | Creates a Superheated Coil, which releases ![]() |
|
Shock and Bomb | Creates a Dynamite-Laden Coil, which releases Dynamite Booty when created or activated. |
|
Flame and Bomb | Summons 3 Fiery Dynamite Booty bots (100% increased health, 30% reduced movement speed). They detonate with ![]() |
|
Flame and Coin | Causes the One-Armed Bandit to fire searing hot coins at all players every 0.5 sec for 8 sec. |
|
Coin and Shock | Creates a Premium Currency Coil, which activates ![]() |
|
Coin and Bomb | Summons 5 Premium Dynamite Booty bots plated with gold. They have 100% increased health, 50% increased damage, and are immune to CC and interrupts. |
|
Enrage Phase:
This phase begins when the boss casts Rig the Game! which forces a specific sequence for the rest of the fight. Each new mechanic
is triggered by the
Cheat to Win! cast.
- Mechanic 1 -
Linked Machines: The boss will now convert Coils into Hyper Coils. These will knock you back and create a
Voltaic Streak beam from the coil to the boss. Standing in the beam does a large amount of ticking damage.
- Tanks: Keep the boss towards the edge of the room to make beam dodging easier.
- Mechanic 2 -
Hot Hot Heat: Random players will get marked and after 5 seconds they will fire a beam from their location to the boss. Ideally the raid will be stacked in a clump and the players affected by
Hot Hot Heat can step to the side of the raid and have a clear path to the boss for their beams.
- Mechanic 3 -
Scattered Payout: The raid will now take additional ticking damage for the rest of the fight.
- Mechanic 4 -
Explosive Jackpot: This wipes the raid.
Heroic Changes:
- All Dynamite Booty fixate adds now apply a raid wide DoT when they explode.
Mythic Strategy
Currently, this tab will only contain information on what changes on Mythic. A more robust strategy will be added after the raid goes live.
Mythic Changes:
- All Reel Assistants have a buff which prevents them from going below 25% health. Roll a
Pay-Line over them to remove this buff.
The Big Hit now creates additional
Shocking Field.
Changelog
- 03 Mar. 2025: Guide added.
This guide has been written by Panthea, who raids in Catalyst and is the author of TankNotes. He plays all tanks and is a Moderator for the Hammer of Wrath Paladin Discord. You can follow him on Twitter.
- Patch 11.1 Nerub-ar Palace Raid DPS Log Rankings
- New Delve Mechanics in The War Within Season 2
- Season 2 Class Tuning: More Beast Mastery Hunter Nerfs & Druid Changes (March 4)
- Liberation of Undermine Raid Guide: Unlock Schedule, Bosses, Loot & More!
- How Gear Upgrades Work in The War Within Season 2: Item Levels, Crest Sources, and Discounts
- Liberation of Undermine Raid Launch DPS Class and Spec Tier List Rankings
- War Within Season 2 Launch Mythic+ DPS Class and Spec Tier List Rankings
- Liberation of Undermine 11.1 Raid and Mythic+/PvP Season 2 Launch Weekly Extended Maintenance Schedule