Posted by: shatteredblog | February 23, 2012

T2 Invention Costs

I’ve been watching the search terms bringing people to the blog for a while. It’s obvious which posts are popular with online searchers, and the one I did about Tipa and I inventing T2 blueprints and the Helios is one that gets hit frequently. This week someone searched “cost of a T2 frigate blueprint” and was guided here, so I thought maybe a talk about the cost of invention would be welcomed. Invention for T2 materials has two costs associated with it, a startup cost and a per attempt cost and it’s best to deal with the two separately.

The startup cost entails buying the skillbooks needed to invent, as well as the necessary data interface for the item you are interested in. All blueprints that have T2 versions require three skills to attempt invention, a racial Encryption Methods skill and two science skills. For ships the racial skills are obvious, but for equipment and rigs you can refer to Chruker’s site for what falls into which categories and which skills and data interface you will need.

The science skills correspond with the skills you can use at research agents and the datacores you buy with rp. The Encryption Methods skillbooks are rarely found while exploring in radar sites, and are common on the market. As I write the most expensive of these is the Minmatar Encryption Methods book, selling for approximately 1.3mil isk. You also need a data interface to make invention attempts, of which there are three types each for the four races. You only need one of these for all the invention you will ever attempt, so I include it in the startup cost. These are made from blueprints and materials also found during exploration in radar sites, and are quite expensive for the ship data interface versions.

Let’s take an example. I decide I would like to start inventing Helios blueprints. My startup cost assuming I have the prerequisites trained already and I’m buying from the Dodixie market would include 850k for the Gallente Encryption Methods skillbook, 9.5mil for the Gallentean Starship Engineering skillbook and 10mil Mechanical Engineering skillbook. I will also need an Incognito Ship Data Interface, the Gallente racial type which would be 40mil. My total startup cost would be 60.35mil isk.

Next is the per attempt cost. This also varies depending on what you are inventing, how you are obtaining your blueprint copies and what your chance of success is. Success chance is a good place to start with this, as it modifies everything else. Your success chance for invention is the result of a simple equation that takes into account the base success chance of the item/ship type, your skill level in the three required skills and any modifiers from optional items you add to the attempt. Let’s skip the optional items for now and just focus on skills.

The site has an excellent calculator you can use to see how raising level in skills affects your invention chance. Going back to our example, the Helios is a frigate with a base invention chance of 30%. With level 1 in the three skills this is increased to 31.51%, by level 3 to 34.61% and up to a maximum at all 5s of 37.8%. These values can be used multiply our cost per attempt to give a cost per successful attempt. For our example, let’s use the level 3 skills number, multiplying our per attempt cost by 1/34.61% or 2.889.

Next you need a copy of the T1 blueprint for the item you are wanting to invent. Often the cheapest way to obtain copies is to make them yourself from an original. Equipment and ship originals are sold by npc corporations, and for light guns, drones, ammunition and the like these are quite cheap. On the other hand, battlecruiser, battleship and mining barge originals are quite expensive and you may be better off searching for copies via the contract system.

Another consideration for copies is the number of runs and material/production level of the copy. While having a well researched copy would be good if you were making T1 items for sale, it is bad for invention as the outcome will always be the same negative level when unmodified by optional items. The number of runs remaining for non ship copies should be as close to max as possible however, as for equipment invention your number of runs on a success is set from 1-10 based on the % of runs vs max left on the copy you are starting from.

For our example, an Imicus bpo sells for 902k so let’s say I’m buying one and adding it to my startup cost then making my own copies, and can hopefully make the investment back later.

Last but not least are the datacores. As mentioned before these correspond directly to the skills needed to attempt invention in the first place, which synergizes well with a character who also has standing to use research agents. Datacores are bought with the rp you gain by working with a research agent or can be directly bought from the market, which can be quite costly. Also remember that in order to work with more than one research agent at a time you need to train Research Project Management, which requires Research V, Laboratory Operation V and 40mil for the skillbook. Different blueprints require different numbers of datacores as well, usually increasing with the size class of the ship or module. For the Imicus blueprint copy, two each of Gallentean Starship Engineering (83k) and Mechanical Engineering (210k) are needed, meaning a per attempt cost of 586k. Also, for public invention slots there will be a small usage fee based on time and standings, amounting to a few ten thousand isk. Accounting for our successful attempt modifier and this gives us a total of 1.75mil per successful attempt.

The last thing to consider is the addition of optional items to the invention process. Optional items are one or both of two things; a meta 1-4 item of the same type which increases the success chance by a large amount, up to a 1.1x modifier for a meta 4 item, or a decryptor which is another item found in radar sites during exploration. Decryptors are expensive items but have massive positive effects on the result, success chance and also the number of runs and also ME/PE. For ship invention, especially higher class ships a Decryptor can be well worth its cost… adding runs to  the max 1 you can normally receive on success. Back on Chruker’s invention page you can see a table of the decryptor types and their effects. I wouldn’t use a decryptor with my Helios attempts personally, as it would significantly increase the cost for small benefit.

How do you value a T2 blueprint copy? In the end it depends on how you factor in the not insubstantial cost of starting up an invention character with the amount an actual success costs you. It’s best if you are interested in invention to either start small if solo, perhaps making drones, ammunition, light weapons or find a corporation that can provide blueprint originals to copy from and data interfaces to use without having to pay for these yourself. Have fun supplying the non-stop demand for T2 goods in EVE!



  1. Thanks to your posts, I’ve been playing again. 😉 Having a blast, as always.

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