Chasing Vex, Ohm, Lo, or Ber can turn an evening of Diablo 4 into a pile of drops that never quite finishes your build. In the Season 15 farming setup described here, the Cabochon Merchant offers a more focused route. For players sorting through Diablo 4 Items, the real challenge becomes managing gold, Forgotten Souls, and repeatable Undercity clears rather than waiting for one lucky reward.
Prepare the Undercity Before Entering
The setup depends on two War Plan nodes working together. Gutter Filth gives Beacon activations a chance to summon a Portal Prankster. Bauble Day connects that encounter to the merchant appearing after the final boss. Activate both before starting. This route suits players who already clear the dungeon comfortably and want a specific crafting target.
1. Activate both required nodes before entering the Undercity.
2. Use Beacons to create opportunities for a Portal Prankster encounter.
3. Defeat one Prankster before completing the final boss.
Keep the Merchant Run Focused
During actual runs, the important decision is whether to check another Beacon or head toward the boss. Missing the required encounter means missing the point of this farming route. Once you defeat a Prankster, finish efficiently and inspect the area around the reward chests. Splinter of Destruction can support the wider run, but it is not essential to merchant access.
Treat Refreshes as a Limited Resource
Reaching the merchant is only half the process. Before spending anything, compare the available stock with your recipe requirements and the resources you can afford to replace.
| Approach | Main benefit | Main limitation |
|---|---|---|
| Buy the target Rune | Immediate recipe progress | Stock and price vary |
| Buy upgrade components | More useful purchase opportunities | Requires recipe planning |
| Continue regular farming | Preserves refresh materials | Less control over drops |
Forgotten Souls fund additional inventory refreshes, so an unsuccessful shopping visit still has a cost. Set a spending limit before opening the stock. A useful Ist, Vex, Ohm, or Lo may offer better progress than repeatedly searching for Ber, provided it fits a confirmed upgrade recipe. Gems and Soul Splinters deserve attention only when they serve another immediate goal.
Prepare the Merchant Trigger Before Entering
Your first task is to create the conditions for a merchant appearance. The practical sequence is Beacon activation, a Portal Prankster kill, and then completion of the District Boss.
Check these connections before starting your run.
• Gutter Filth gives Beacon activations a chance to summon a Portal Prankster.
• Bauble Day makes the Cabochon Merchant appear after the District Boss when you have killed a Portal Prankster during that run.
• A run without a Portal Prankster kill does not satisfy this merchant trigger.
Prioritize reachable Beacons while maintaining a successful clear. Since the encounter is uncertain, consider combining this setup with your existing Rune-focused Undercity runs instead of making the merchant your only reason to enter.
Set Purchase and Refresh Limits
Your second task is to protect the resources needed to keep farming. Inventory refreshes consume Forgotten Souls, while purchases consume gold, so repeated shopping can exhaust two different reserves.
Use these checks to keep the session focused.
• Refreshing the merchant creates another stock opportunity without guaranteeing your target Rune.
• Tribute of Refinement and Greater Tribute of Refinement rewards include Forgotten Souls.
• Patch 3.2.1 addressed incorrect Cabochon Merchant inventory pricing and quantity displays.
Write down the exact Runes your intended craft needs, then reserve enough gold to buy them before spending heavily on refreshes. Check the displayed quantity and total price before confirming; a recognizable Rune name alone isn't a reason to purchase.
What Should You Do Before Your Next Undercity Run
Check Gutter Filth and Bauble Day, choose your target Runes, and decide how much gold and how many Forgotten Souls you're willing to spend. Use that same target list when reviewing cheap Diablo 4 Items so your next purchase matches an actual crafting need. Stop shopping when the remaining resources matter more to your current goals.
