I really like the hacking system in Fallout; I think it's quite elegant. I'm very curious as to whether, if you are making a correct logical choice each try, it is mathematically impossible to lock a terminal in Fallout 3 or 4.

These are my basic assumptions of the system so far.
- Each screen has ten words, in addition to a RESET TRIES and a DUD REMOVE. (not sure what percentage of the time these two appear).
- Each word is related to another word in the list by a minimum number of letters based on the length of the word (i.e. a 4 letter word will have at least 1 likeness with another 4 letter word, seven letter words will have at least 3 likenesses. I'm not 100% certain this is true, and I'd love to know the math on this.

- Each word probably has some variance calculation so that there aren't too many words in one group of likenesses, i.e. 10 'ING' words with 5 'B' prefixes and 3 shared letters in the center.

MY THEORY is that if you select a word, then select another word that has a correct number of likenesses to word 1, then select a third word that has a correct number of likenesses to word 1 and 2, it is mathematically impossible that the fourth word you select (matching all three likenesses) will be incorrect apart from human error. But I don't actually know for sure. Would a Bethesda person be willing to shed light on how this works? Has anyone else done the math?

You can exit the terminal on your last attempt if you're stumped. The counter restarts when you access the terminal again.

And it probably isn't mathmatically impossible. Especially in Fallout 3, I've ran accross 5 words ending in "ing", and burned through three attempts, each one saying that 3 letters were correct. That meant I literally had a 50/50 chance that the next "ing" word I chose was the correct one.

And this is assuming that each one of those "ing" words actually had the letters "ing" correct. With hard or very hard terminals, it's entirely possible that I was wrong in assuming that the right word ended in "ing".

I still can't figure out the dud remove and reset tries in Fallout 4 on the PS4.

Bracket strings, Carbon Dragon. That's what you're lookig for.

( and ), < and >, { and} , [ and ] all are reset tries/dud remove entries, and I believe there's no way to tell which is a dud remove, which is a reset tries, but they are the 'special' entries. There may be some key to it, regarding how many characters are in the string between the brackets, but I really don't know.

the hardest part in my view is if you unluckily select words with no likeness, as you said its genuinely quite easy even not using the dud removal or extra tries, in fact i believe it's actually easier to hack harder locks on computers because the increased difference between each word. I can hack master computers within 2 or 3 tries consistently whereas a novice one can be unpredictable and may require the dud removal.

Reset tries aren't guaranteed, but there are going to be at least 3 dud removals every terminal. Not so sure if that's true for higher level terminals, as I have little experience with them in both games.

It is entirely possible to fail a hack even with an optimized and calculated method. From personal experience, if you fail to find likeness in even one word, you won't have enough tries left should you not get lucky.