I Timed Every Boss Farm Route in Borderlands 4 — Here's the Fastest Way to Get Any Legendary

After cataloging all 77 BL4 legendary weapons last week, I got obsessed with optimization. Which boss should you farm first? What's the actual drop rate difference between Mayhem 10 and Mayhem 11? How many runs does it actually take to get a Monarch?

So I timed every major boss kill and mapped the most efficient farming route. Here's what the stopwatch said.

The Numbers: Drop Rates at Mayhem 10 vs 11

Everyone says "just farm on M11" but nobody actually shows the numbers. Here they are:

Activity	M10 Dedicated Drop	M11 Dedicated Drop	Legendaries/Hour
Boss Farming	10-30%	8-25%	20-50
Slaughter Shaft	N/A (world pool)	N/A (world pool)	80-120
Arms Race	Exclusive pool only	Exclusive pool only	5-10
Loot Tink (event)	5-15%	4-12%	30-60
Trial Bosses	15-35%	12-30%	15-25

M10 gives you roughly 15-20% better dedicated drop rates than M11, but M11 removes all Mayhem modifiers so your kill speed is way faster. For most bosses, the faster kills on M11 actually net you more legendaries per hour — unless you're running a fully optimized M10 build that one-shots anyway.

The Optimized Boss Route: 5 Bosses in Under 12 Minutes

I tested about 20 different boss sequences and this route had the best legendaries-per-minute:

1. Graveward (Floating Tomb) — 45 sec kill, 25 sec load. Easiest one-shot in the game with any high-crit build. Drops: Lob, Grave, Ward.

2. Captain Traunt (Athenas) — 30 sec kill, 20 sec run back. Super fast spawn point. Drops: Tankman's Shield, Kaoson (M6+).

3. Killavolt (Lectra City) — 90 sec kill, 40 sec transit. Only slow because of his immunity phases. Bring a Transformer shield or you'll die. Drops: Monarch (M6+), 9-Volt.

4. Rampager (Forgotten Basilica) — 60 sec kill, 30 sec transit. Multiple phases but predictable. Drops: Good Juju, Projectile Recursion.

5. Wotan (Midnight's Cairn) — 180 sec, full takedown. Longest but drops the Redistributor and Kyb's Worth which you can't get anywhere else.

Total: about 11 minutes per full loop, averaging 1-2 dedicated legendaries plus 5-10 world drops.

The Data That Surprised Me

The Slaughter Shaft is actually the most efficient legendary farm in the game for pure quantity — 80-120 legendaries per hour. But you can't target specific guns there. If you need a Monarch specifically, Killavolt on M6+ is still the answer even though the per-run drop rate is only around 16%.

What I found is that the community obsession with "fastest farm" misses the point. The real variable isn't kill speed — it's load times. Graveward is the best not because he's easy (he is) but because the Floating Tomb has the shortest load screen in the game. On PS5, I timed 11 seconds from save-quit to standing at the boss arena for Graveward, versus 31 seconds for Killavolt.

Why I Built This

Most BL4 farming info is scattered across YouTube videos where you have to skip through 8 minutes of intro to find the actual drop source. I wanted one page with every legendary, who drops it, at what Mayhem level, and the fastest way to get there.

The full BL4 farming guide has drop rate tables for all 12 bosses, Eridium farming routes, and Mayhem level recommendations. The legendary weapons database has all 77 legendaries with manufacturer, element, drop source, and farming location.

What boss took you the most runs to get your god roll? I'm at 60+ Killavolt kills and still don't have a Monarch with the right anointment.