One topic which comes up OFTEN in the Crew Skills forums on SW:TOR is people complaining about how long it takes to get the schematics they want. We’ll often see “I’ve reverse engineered 30 of these things and haven’t gotten a schematic! It must be broken!” Unfortunately, the real answer is that they are simply the victims of bad luck (or bad record keeping … but we won’t go there).

# Chance of RE Success

Each time a crafter reverse engineers an object, they have a 20% chance of finding the schematic (there are a few exceptions where it is 10%, but let’s stick with 20% for now). This means that there is an 80% chance that RE’ing an item does NOT produce the desired result.

## Sidebar – 1 in 5?

Unless one has studied mathematics (or more properly statistics), it is easy to see 20% meaning that I have a 1 in 5 chance of getting a schematic as a result. Logically, one may think “Then if I RE 5 implants, I’ll get one for sure, right?” But that doesn’t weigh out in the end. To see why, it may be easier to think of a coin flip.

Each time you flip a coin, there is a 50% (1 in 2) chance that it will land on heads. That means that if you flip the coin twice you’ll definitely have at least one ‘head’ result, right? No, unfortunately, that’s not right. If we think of the possible results from flipping a coin twice, we have the following…

Flip 1 | Flip 2 |

Heads | Tails |

Heads | Heads |

Tails | Heads |

Tails | Tails |

So, with our coin flip example, there is a 1 in 4 chance that by flipping twice, you’ll get no head result at all. In statistics, this sort of phenomenon is commonly calculated by using what is called a binomial distribution function.

# Likelihood of a Schematic

If we’re answering the question “What is the likelihood that I’ll get at least 1 schematic by reverse engineering a certain number of items?”, it is somewhat counter-intuitive but we actually get the answer by asking the reverse question “What is the chance that we will **FAIL** to get **ANY** schematics by RE’ing a certain number of items?”

Using a binomial distribution function, we can calculate the chances that we fail to receive a schematic depending on how many items we RE. See the spreadsheet attached to this article for more info, but for now some samples at various points are good enough:

Attempts | Failure% | Success% |

1 | 80% | 20% |

5 | 33% | 67% |

10 | 11% | 89% |

15 | 4% | 96% |

20 | 1% | 99% |

First point to mention is that while we might have thought logically that by RE’ing 5 items, our “1 in 5” chance should work out to 100%, it’s actually only 67% likely to produce a schematic. We’ll have to go higher to be more confident of our results.

We can see that by this chart, that there is a 96% chance that once we’ve RE’d 15 items we will have received a schematic. The chances never quite get to 100%, however by the time you get over 20 attempts, you’re only going to fail to receive a schematic less than 1% of the time. Even at 50 attempts, there is still a 0.0014% chance that you won’t find a schematic; so it CAN happen!

I tend to use the 96% threshold as my target that I’m comfortable with. Much higher and I’m likely to be wasting too much time / resources.

# But I Don’t Want Just ANY Schematic!

The reality is that most players don’t just want to be able to craft ANY item, they want a SPECIFIC schematic. At times there can be as many as 3 new schematics to learn from a given item. Since I’m working on some of my Tier 11 implant schematics, I’ll use those as an example.

An Anodyne Might Package MK-1 can be reverse engineered into 3 variants (Expert, Fervor, or Veracity). If what I want is the Expert schematic, then the fact that I can feel confident of getting at least one of the 3 by RE’ing 15 items isn’t enough. Sure, it could work out that the first schematic I get is the one I want, but Murphy seems to love Random Number Generators; so let’s assume I need to find more than one to be SURE that I have what I want.

The good news is that this time math is in our favor. 🙂 I won’t have to do 3 times 15 (45) items to RE to get my Expert schematic.

## Finding 2 Schematics

Again using the binomial distribution function we can calculate what the chances are that we find less than 2 schematics. Inverting this number gives us the chance of finding 2 schematics in our RE’ing attempts.

Attempts | Failure% | Success% |

2 | 96% | 4% |

5 | 74% | 26% |

10 | 38% | 62% |

15 | 17% | 83% |

20 | 7% | 93% |

25 | 3% | 97% |

30 | 1% | 99% |

This means that we can reasonably expect that 97% of the time, if we RE 25 items, we’ll have discovered 2 schematics. Since we’re assuming there are 3 total schematics to be learned, there is a 66% chance that at this point we have found the schematic we need.

## Finding 3 Schematics

If we’re curious about what it would take to feel certain that we find our target schematic, then we’d need to figure out the chances that we find all 3 possible outcomes. The table for this is as follows:

Attempts | Failure% | Success% |

3 | 99% | 1% |

5 | 94% | 6% |

10 | 68% | 32% |

15 | 40% | 60% |

20 | 21% | 79% |

25 | 10% | 90% |

30 | 4% | 96% |

35 | 2% | 98% |

40 | 1% | 99% |

This means that if we’re looking for that 96% confidence factor, we need to plan to RE 30 items. Note, however, that after 15 attempts, we are at 60% (better than a coin flip). So the extra 15 attempts only really add 36% to our confidence that we’ll find what we want.

## It’s All About Artifacts

So, to have a 96% confidence that I’ll find the desired Prototype (blue) schematic, I re-engineered 30 items. However, the end-goal is really to create a Hawkeye version of the implant. The Prototype Expert implant can yield 3 different Artifact schematics (Expert, Hawkeye, and Vehemence). So I am basically duplicating what I did to get the Prototype Expert in order to get my Artifact Hawkeye implant. I’ll have to plan on making 30 Expert Anodyne Might Package MK-1 implants in order to find the schematic for Hawkeye.

# Throwing Away Resources

My personal belief is that the frustration people have with the Re-Engineering process is not the success rate per-se. It’s more because they are creating 15, 20, 30, or more items that they **DON’T** want in order to get the schematic for the item they **DO** want to create. This represents a “waste” of resources in many people’s minds. Whether those are the credits used to buy materials, the materials themselves, or the time to craft “junk” items.

## Resource 1 – Time

It takes approximately 5 minutes for one of my characters to create a single Anodyne Might Package MK-1 implant. I need to plan on making 30 of them. Since at level 56+ you can have 6 crew members crafting at any one time, and each can queue up 5 items each, I’ll need to plan on one full cycle of my crew to get my Expert schematic. That’s 5 times 5 minutes = 25 minutes.

Then, I have to do it all over again with the Expert to get the Hawkeye. Expert implants take longer, though. They require 28 minutes in fact; so a total of 140 minutes (2 hours, 20 minutes). Which brings my total time (assuming I’m perfectly efficient) to 2 hours and 45 minutes to find the schematic I want. And remember there’s still about a 4% chance that either of those steps failed.

## Resource 2 – Materials

The other factor involved in the dissatisfaction is that you “waste” a lot of materials just to get your desired schematic. In my example, I created 60 implants whose sole purpose was to discover the schematic for the one I really wanted to create.

Anodyne Implants require 2 Synth-Net Implant Processors, 2 Metamorphic Cell Cultures, and 2 Anodyne Extracts per implant. The Expert Implants add 4 Hemostatic Gels to the above. That means I used a total of 120 Processors, 120 Cell Cultures, 120 Extracts, and 120 Gels. All “wasted” in pursuit of a schematic.

**Sidebar**: I know that the reverse-engineering process can also return some of those materials. However my experience has been (at least at the Tier 11 level where I have tracked it) that the amount returned is too small to factor into the calculations of required resources.

## Psychological / Emotional Impact

Interestingly enough, our brains are made to enjoy the risk/reward cycle. Studies have shown that when a gambler is playing the slots, their endorphin levels (the chemicals that make you feel happy) peak just *BEFORE* the dials stop spinning. Even if they win, the peak chemical enjoyment of the process is the **anticipation** of getting what you want.

However, the problem we see in this dissatisfaction is that over time you stop believing that you could win. As you reverse engineer item after item, eventually you stop believing that you’ll get the schematic. It stops being exciting to see if the schematic drops or not, you’re just frustrated with having to keep clicking.

### Too Much Success?

So here is an interesting twist. As I mentioned, if I want a 96% chance that I’ll find the schematic I want, then I’m going to produce 60 implants (30 Premium (green) implants and 30 Prototype (blue) implants). However, if Lady Luck were to smile on me, I might only have to create 2 (1 of each). I could hit my 20% chance on each one and then the 33% chance that the schematic which procs is the one I’m trying to find. I wouldn’t bet on it, but it could happen. (Btw, if it ever **does**, I’m running out right away to buy a lottery ticket!) Regardless of the likelihood, the lucky happening ends up creating another issue.

Basically if I made 30 items and only actually NEED 2 or 3 to get the schematic I was looking for, then the other 27+ of them feel like a huge waste of effort. That might be ok once. But when you figure there are 17 different Tier 11 implant lines to make for a biochemist, if it happens more than a couple of times, it actually starts feeling like a negative.

## Completionists Beware

If you have the unfortunate luck to be like me, and you want to find ALL of the Tier 11 schematics, be prepared. If you look at my Gap Analysis spreadsheet, you’ll see there are 51 Prototype and 153 Artifact implant schematics which can be learned for Tier 11. A total of 204 learned schematics to discover. If I’m making 30 “throwaway” schematics each, that means I have to make over 6000 implants that (technically) I don’t need. I’ll spend a bit over 12,000 of each resource in pursuit of this silly goal. Not to mention almost 16 DAYS of active crafting time.

**Side note**: It IS silly. I realize that. But I’m having fun; so I don’t care about the waste of time/credits.

The only positive? 6000 Tier 11 enhancement slot pieces (which currently retail for an average of 5500 credits each); so at least I’ll make about 3 million credits selling that junk. My balance seems to mostly be stable as I buy resources from the GTN and sell enhancement components.

# Solution?

Barring a change in the RE process (which I wouldn’t count on if I were you), there isn’t a very good solution to the “problem”. In fact, from a game system design point of view, it isn’t really a “problem” in that it is working as designed. However, there are a couple of things that you might do in order to reduce the frustration levels.

## Multiple Targets

I have a slight advantage in that I can have each of my 6 crew members working on a different Implant line. It makes me feel like I’m making more progress because I have more targets than only wanting to get 1 Artifact schematic. You might consider pursuing more than one final schematic at a time. It may take more time to get any specific schematic, but at least it will feel a bit better as you’ll make progress on almost every crafting pass.

## Reduce the Investment

If you’re willing to trade time for resources, you could build the “junk” items in smaller batches. This would likely reduce the overall waste since by my tables the first 15 items give you a 60% chance of success. That means that the second 15 in my plan are only giving me another 36% confidence. If you did things in batches of 5, you could stop as soon as you find the schematic you’re looking for. Overall time investment would be higher (as you’d need to micro-manage your crew a bit to accomplish this), but it would require fewer resources.

## Stop Worrying?

Ok, I know this sounds like a “Life isn’t fair, get over it” argument. But it might help you out to simply accept that the system does work in the way it is designed. I think (as a rule) much frustration in life comes from the fact that reality doesn’t match how we wish things would be. Sometimes you can be the change that you want there to be. In this case, there isn’t much we (as players) can do to influence this system. So accepting that it is the way it is may be the best approach in the end.

## Attachment

The spreadsheet that I used for the stats in this article is attached. It includes some data beyond my summary here. Also, as a “bonus”, I include one sheet from the workbook I use for tracking the recipes my crafting characters have discovered. I used the Tier 11 Implants sheet. It can be adapted fairly easily to other crafts as well.

SWTOR Crew Skills – Reverse Engineering

## xaeus Said:

on March 24, 2015 at 8:10 am

For non-sub players the chance is half (10% or 5% instead of 20%/10%). I recently had to make 44 green barrels to get 1 blue schematic.

Probabilities mean nothing. It’s just like in a religion… you have faith in something…and it may happen or not.

Math does not seem to help since sometimes there are no actual returned schematics for many many dozens of REs while in other situations you can have 3 schematics out of 4 REs (It seems the random chance is not so random after all, maybe other variables involved).

The percentages are just a basic reference. Just as in theory you could RE indefinitely without getting a drop, because second, third etc. REs does not increase the chance of a schematic drop.

If the chance is 10% the first time, it will be the same the second time…and the 100th time. Each RE event is independent. The game does not take into account how many REs you performed.

An anomaly also seems to manifest sometimes in rolls. Long time ago I rolled 8 consecutive (consecutive as in under a few seconds total) rolls of which only one was 11 (with 7 of them under 10).