When I compare the rules for Extended Tests in DH2 core rule book with the table on crafting things (in the same book) and the explanation on Gate of Infinity in the FAQ pdf I get a little confused ... Are extended tests always a number of tests? I thought for crafting one test needs some random time and then one counts the number of successes and only if this is below some predefined target number then another test and so on until one has the needed number of successes. So why would I have to role 3 tests for Gate of Infinity? Wouldn't it make more sense to say one test for this power takes 3 rounds and the psyker has to score let's say 3 successes or something like that? Is my interpretation of the crafting rules wrong?

I see what you mean. Doing multiple tests can represent the character doing different things. Say three Trade(Armor) tests for creating a weapon: One to design it, one to build it, one to find the quality (2 DoS = more quality). Or you could just use one roll to represent an abstracted, slightly more narrative span of time associated with an action. "Build the weapon. You need 5 degrees of success to succeed (equivalent to a -40 roll), each extra success increasing the quality". Ultimately it is up to the GM to decide which works best for them in any given situation.

(Note that these are not statistically equal. There is a 12.5% chance to roll target of 50 three times in a row, and there there is only a 10% chance to roll 5 degrees of success on one 50 target roll. Additionally, its impossible to increase the quality to Best in the single dice roll scenario).

I personally like the first approach, but I've had GM's who just want one roll. One roll seems to understate the length of time and skill required, IMO. Alternatively, the GM could describe these three stages to add a little more gravitas, instead of having them rolled separately

I'd just go with: You need 5 degrees of success. If you get them with one roll: Good for you. You excelled really good at the task and finished it in one intervall. If not: Spend the requiered amount of time again and roll again. Add/Subtract the DoS/DoF to the total. If the total is 5, you did it. If the total is reduced to zero or you botch, you fail at the task and the materials are lost.

Else: Continue ad nauseam.

When I compare the rules for Extended Tests in DH2 core rule book with the table on crafting things (in the same book) and the explanation on Gate of Infinity in the FAQ pdf I get a little confused ... Are extended tests always a number of tests? I thought for crafting one test needs some random time and then one counts the number of successes and only if this is below some predefined target number then another test and so on until one has the needed number of successes. So why would I have to role 3 tests for Gate of Infinity? Wouldn't it make more sense to say one test for this power takes 3 rounds and the psyker has to score let's say 3 successes or something like that? Is my interpretation of the crafting rules wrong?

I think you may be mixing up extended actions and extended tests.

I do not have the book in front of me so I will check it later to be sure, but from the sounds of it and if my memory serves; the extended test for casting or combat is only one test or declaration of action and then takes that many turns. In abstract time, as the others have stated a single or multiple rolls can be used based upon GM discretion.

For example reloading a plasma gun takes like five turns. In combat if it jammed you would roll your test and if you succeed, it would take you said five turns to get it functional but it would only need your first successful roll. Or in your example, casting gate of infinity. One test to manifest the power and then however many turns it describes for the extended action before it takes full effect.

When I compare the rules for Extended Tests in DH2 core rule book with the table on crafting things (in the same book) and the explanation on Gate of Infinity in the FAQ pdf I get a little confused ... Are extended tests always a number of tests? I thought for crafting one test needs some random time and then one counts the number of successes and only if this is below some predefined target number then another test and so on until one has the needed number of successes. So why would I have to role 3 tests for Gate of Infinity? Wouldn't it make more sense to say one test for this power takes 3 rounds and the psyker has to score let's say 3 successes or something like that? Is my interpretation of the crafting rules wrong?

I think you may be mixing up extended actions and extended tests.

I do not have the book in front of me so I will check it later to be sure, but from the sounds of it and if my memory serves; the extended test for casting or combat is only one test or declaration of action and then takes that many turns. In abstract time, as the others have stated a single or multiple rolls can be used based upon GM discretion.

For example reloading a plasma gun takes like five turns. In combat if it jammed you would roll your test and if you succeed, it would take you said five turns to get it functional but it would only need your first successful roll. Or in your example, casting gate of infinity. One test to manifest the power and then however many turns it describes for the extended action before it takes full effect.

Gate of Infinity is a corner case. It's addressed in the current FAQ and requires 3 Focus Tests to "cast."

Otherwise, extended actions either require no test (reloading) or a test for each amount of time, whereby successes are gathered after a certain number of which the task is complete.

afaik... :-D