## Rares Explained

*Article by: Odok @ winterwolves.org*

### I Had It In My Hand — Archaeology Rares Explained – **Odok** – Jan 5, 2011

There’s been a lot of grief over Archaeology rares lately, either for collectors like myself or people who actually want an epic for raiding. Everyone assumes that rare artifacts are, in actuality, rare “drops” in your project window, but I’m here to tell you that they may not be as rare as you think, but only in certain circumstances. How? It has to do with how the game tosses the dice to see what your next project is.

Basically, it rolls a number and checks it against the total list of all possible artifacts. Rares are, obviously, harder to hit and it’s possible that the epic rares have the lowest drop rate of all (as compared to, say, the kaldorei wind chimes). If the game lands on an item the player is not eligible for, it rerolls. This is the important part. There are only three main reasons a player can be ineligible for an artifact: 1). Their skill is too low 2). It’s a rare the player has already completed 3). It’s a repeat of a common artifact when the player has yet to complete all available common artifacts. That third point is how you can effectively “cheat” the system.

I don’t know enough about probability or coding so I can’t outline the proof, but basically, you have a higher chance of getting a rare when it’s coupled with incomplete commons than its actual drop rate would suggest due to these free rerolls. In fact, the probability of getting the rare increases each time you complete another common until you’ve completed all the commons. This is why you usually get a rare early on in your archaeology career and why they suddenly get so much harder to find later on since you’ve usually finished all the commons before the really juicy rares show up.

I’ll use Zin’rokh as an example, since it’s the most infamous rare and because it makes for a perfect example of what I’m talking about. Let’s say it has a 1% chance to appear as a project. Zin’rohk can’t appear until you have a 450 skill in Archaeology, yet new troll commons stop appearing at around 250. Since most people start leveling Archaeology in the Eastern Kingdoms (since it has a better spread of all four starting races than Kalimdor’s 50% Night Elf spread) and Troll dig sites appear in Northrend, it’s a safe bet that a very high number of people have finished troll commons by the time they hit 450 skill. This is consistent with the numerous reports of people solving 300-500 projects before getting a Zin’rokh… or not even by then. Since the whole list is always available from the beginning the drop rate is a true 1% chance.

However, let’s look at the numbers assuming you haven’t solved a single troll common until 450 skill. There are 14 troll commons, so assuming the 1% chance on Zin’rokh, each common has a ~7% chance to drop (7/99 to be precise). So after you solve your first project, you have a 1/92 chance of getting Zin’rokh, since that first common or 7/99 chance has been made ineligible. That’s still only around a 1% chance, though. The next time it’s a 1/85 chance, again still pretty low. But that fraction keeps getting smaller and smaller. **By the time you’re down to your last common and Zin’rokh the chance to land on the rare has increased to 1 in 8, or 12.5%!** In fact, just by taking the probability of the whole system modeled here, you have a 42.75% chance of getting a Zin’rokh before finishing all of your commons.

Interestingly, this also means that races with fewer commons also make it harder to get the rares using this method. This is easily seen with the high-level races that have their epic rares available from the moment you can start finding their dig sites, yet have far fewer commons. For example, Vrykul only has 5 commons and the bearded axe rare. Assuming the axe only has a 1% drop rate as well, that’d mean the commons each have a 19.6% chance to appear. So with one common left, you still only have about a 5% chance to get the axe, with a 10.27% chance of getting the rare before running out of commons. So that’s why Tol’Vir stuff is so hard to find even though everyone automatically uses this superior method – they only have 8 commons for 6 rares. Even though it seems like with so many rares it should be easy to get at least one of them, you still only have a 22.3% chance of getting ONE of the six rares before running out of commons (assuming a 1% drop for each, which might not be the case) with only an 8.6% chance of getting a rare on the “last” solve.

This is by no means confirmed, but it’s the most logical and efficient way of modeling the system and seems to be supported by the data people are reporting. So, in short, if you’re after a particular rare in Night Elf, Dwarf, or Troll don’t solve any projects for them until you hit 450 skill. If you’ve already screwed yourself over, regrind Archaeology on an alt. Trust me, it’s a better time investment than trying to hit 1% on a project. If you’re after a Tol’Vir BOA weapon or other rare, good f-ing luck. This is also why, instead of asking for the ability to specify dig sites, you should be asking the devs to add more tol’vir commons.

*Above text from: http://www.winterwolves.org*