For information on the basics of the refinement system, see: http://irowiki.org/w...finement_System

This page assumes level 4 weapons or armor unless otherwise specified.

Going from +4->+7

The best choice for going from +4->7 will vary based on the cost of the item, and how you value enriched ores. This calculator will give the average cost, and how many +0 items will be needed (on average) to make a +7.

http://drazzy.com/calc/upgrade.shtml

Going from +7->+9

Using enriched hammer to do +7->9, you'll average 40 enriched per +9 (median 26 - it's thrown off by the long unlucky tail). 90% of attempts will be successful within 94 or fewer enriched.

Using normal HD to do +7->9, you'll average like 258 HD per +9 (median 174). 90% of attempts will be successful within... uh... 616 HD

So - enriched is 26 KP now, so enriched to +9 averages 1040 kp (median 676), with 90% of attempts costing under 2450kp. (with enriched box 50: 760, 494 and 1786, respectively)

HD is 10kp each, so enriched to +9 averages 2580 kp, (median 1740), with 90% of attempts costing under 6160 kp.

At 2 seconds per attempt (an aggressive target), we're talking a minute and 20 seconds with enriched, and 8 minutes with HD. The time spent upgrading is significant, since if you're unlucky

So using HD, you'll spend 6 times longer pressing buttons and spend 2.5x (3.5x with enriched 50 boxes) as many kafra points.*tl;dr: Don't ever try to make a +9 without enriched hammer.*

Going from +9->+10

The success rate going +9->10 is 10% (for level 4 weapons and armor). The options are to do HD Ori/Elu, or to use Safe to 10 Certificates. But which is the better option?

On average, it will take 10 attempts to get +10, 9 of which will fail.

So the cost to +10, on average, 10x cost per attempt, plus 9x cost per failure (plus the +9 you started with, of course).

That means, using safe certs, the cost of making a +10 averages ten times the cost of a Safe to 10 Certificate.

Using HD, and one of the Hammers to get back to +9, the average cost is 10 HD's (100kp), plus 9x the cost of going +8->9.

Using HD w/mighty hammer: Average 208 HD, median 115, 90% within 555 HD, with costs of 2080, 1150, and 5550 kp respectively. This places the cost at 18820 KP from +9->10! This also involves 41.6m zeny in upgrade fees (!!!)

Using Enriched Hammer: Average 29, median 13, 90% within 79, with costs of 754, 328, and 2054 respectively with boxes of 10, (551, 247, 1501 with box of 50). This gives us a cost of +9->10 of 6886kp with boxes of 10, and 5059kp with boxes of 50. Upgrade fees are 5.8m either way.

So, to bring this back to safe to 10 certs:

If there is no enriched hammer event running, safe cert replaces 1882 kp of HD ore and 4.1m in upgrade fees, and is almost certainly cheaper.

If there is enriched hammer with boxes of 10, safe cert replaces 687 kp of ore.

If there is enriched hammer with boxes of 50, safe cert replaces 506 kp of ore.

The value of KP and safe certs vary over time and between servers, so I can't say which is a better deal where, but that is what you should compare the cost of a safe to 10 cert when deciding whether it's worth the expense of using them.

Going beyond +10

There's nothing fancy here, since the rate is constant, and there is only one way to approach it. The rate is 10% for lvl 4 weapons and armor, 20% for level 1-3 weapons. Don't even think of using non-HD Bradium/Carnium.

Since the whole thing is simpler, I've just provided averages.

So, for lvl 1-3 weapons:

Average 5 attempts to get a +11

Average 5 attempts at +11->+12 to get +12, so 5*(5+1) = 30 HD Bradiums to go +10 -> +12

Average 5 attempts at +12->+13 to get +13, but it goes back to +11 on fail, saving you 5 HD bradiums, so 5*(30+1)-4*(5)=135 HD bradiums to go +10->+13

Average 5 attempts at +13->+14 to get +14, by same reasoning, 5*(135+1)-4*30 = 560 HD bradiums

+11 - 5 HD Brad

+12 - 30 HD Brad

+13 - 135 HD Brad

+14 - 560 HD Brad

Again - these are all averages.

For lvl 4 weapons and armor, by identical reasoning:

+11 - 10 HD Brad/Carn

+12 - 110 HD Brad/Carn

+13 - 1110 HD Brad/Carn

+14 - 11110 HD Brad/Carn (yes, that's about $2 grand worth!)*tl;dr: Don't try to go beyond +12 on armor or lvl 4 weap unless you're both rich and stupid.*

**Edited by DrAzzy, 28 November 2013 - 07:04 PM.**