With the exception of Jah & Zod, the best, most efficient way to get high-runes on single-player is to do Lower Kurast runs.

What is a Lower Kurast run?
There are special chests in Lower Kurast that, unlike sparkling chests, don't stand out.
These chests have a unique drop-table of 65,536 (256 x 256) possibilities... at least 66 of them (On Players 7 or 8) have been confirmed to be Mal+, for a 0.1% chance, or 1 in 1,000 chance.

How do you identify these chests from the others?
The first thing to look for are these campfires surrounded by torches.



















Secondly, nearby these campfires, there are always two huts, one to the left of it and one to the top right of it. The top right has one special chest and the left has two special chests, as marked above. Here are pictures of the chests to differentiate them from the regular poppables in the area. (Because they really don't appear to be special).







































It is possible to re-roll your map (By switching difficulties back & forth) until you get a map with 6 of these chests (Preferably close to the waypoint). Like so:
















If you get a map like that, once you find a rhythm, you can do roughly 1 run every 25 seconds or about 150 runs per hour. 150 runs per hour means you should be finding a Mal+ rune at an average rate of every hour or so. However, if you take downtime into consideration, like emptying your inventory and whatnot, it's more like a high rune ever hour & a half.

However, Ber is far less common than any of the others. Expect a Ber  every 5,000 runs or so, while it's quite possible that you could even run 10,000 runs and still not find one. It's actually more likely that you'll find two Sur runes to cube into Ber than get a Ber to drop.

This takes patience, LOTS of patience. In fact, if you're anything like me, the monotony will drive you MAD. I stay focused by trying to work on other things these runs help with, namely crafting caster amulets (Ammy + PAmethyst, Jewel, Ral) and blood gloves (Vampirebone Gloves + PRuby, Jewel, Nef)

These runs produce a LOT of charms, jewels, and flawless gems if that's something that interests you.

As for Jah & Zod, well unfortunately there isn't such a reliable method of getting these. The best advice I can give you is to farm The Pit in Tamoe Highland in Hell Difficulty on Players 8. Your odds of getting one are still dismal, even if you run it hundreds or even thousands of times, but it's the most efficient way to get one. Alternatively, you could get two Ber from Lower Kurast and cube them into a Jah, but as mentioned before, Ber is very elusive.







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