I've been doing a nature rune run recently and figures out that I crafted 1k ess into nats and gained a total amount of 1,4k nats. this is aprox 40% more then you would receive before the "extra runes" update. So I started thinking around, and figure out a basic formula to get the maximum amount of extra nats you receive rc'ing. For nats we know you get 1x at lvl 44. For nats we know you get 2x at lvl 91. I am runecrafting lvl 61. 91 - 44 = 47 61 - 44 = 17 17 / 47 = 0,36 0,36 * 100 = 36 My conclusion is simple, I have a 36% chance to gain extra nats, I crafted aprox 1k ess and gained aprox 1,4k ess, coudl be slightly less as I didn't do exact easurements on crafting the runes. I think the formula is kinda close to what it is in reality. Also, I crated law runes, which don't have a 2x multiplier, and I didn't gain any single "extra" law rune while crafting, therefore I consider any runes crafted without a next multiplier (1x to 2x, 2x to 3x, 3x to 4x etc) will not allow you to gai nextra runes. So I guess after 91 for nats you will not gain any extra nats as there is no 3x multiplier for nats. [edit] Something new I figures to my theory: I have 28 inventory slots, using 3 pouches, having each 3, 6 and 9 ess (total of 18 ess), leaving 25 free slots for ess. As you get to the altar, you craft your 25 ess into nats. 36% of 25 = 25 / 100 * 36 = 0,25 * 36 = 9 with my 25 ess, I gain a maximum of 36% extra nats, which results in 9 extra runes at max. 9 extra runes at max, 9 runes represent a 100% extra nats I would gain, which is very unlikely to happen, so I started thinking of a possible formula. Let's say I make 50% of the extra nats, so I'd make 4,5 (rounded up a bit makes 5 nats). Doing the same calculation on the remaining 18 ess in my pouches which you craft separated from these 25 ess, this is what you get: 36% of 18 = 18 / 100 * 36 = 0,18 * 36 = 6,48... rounded down (as rs likes to round down) makes 6 extra nats. again these 6 represent 100% extra nats, let's say I make again 50% extra only, so I make 3 extra nats. 25 nats + 18 nats + 5 extra nats + 3 extra nats = 51 nats Indeed, I can confirm I prety often made 51 nats... doing some more thinking, I came up with this: as 9 nats are 100%, 1 nat is 11,11%, so if I have made 0 extra nats, I'd have 0% chance to fail making an extra nat, so I make 1 extra atleast. Having made 1 extra nat, I have 11,11% chance to fail making a 2nd extra nat. Having made 2 extra nats, I have 22,22% chance to fail make a third extra nat. etc etc... Having made 5 extra nats, I have 55,55% chance to fail making a 6th extra nat, this is fairly much fail chance, a 55% fail chance, so it's likely impossible you'd make 6 extra nats. so basicly, I think this could be a possible formula or calculation to how much nats we make on average aswell as minimum and maximum. I just guess with ome logical thinking, I am not certain, nor is it confirmed by jagex or any other tests I performed doing altar runs, I just based off some logcal thinking and the 1 run I made myself which made me start thinking about it :P