Someone please refresh my memory. What happens when you fail 4 times hacking a terminal in Fallout 3? Plus, Do you get a scond chance? Thanks.

It locks you out. You can only hack it after that from having a perk that allows you one more chance after lock-out, and then you can't do anything with that terminal ever again.

You're locked out. There's a perk that let's you get a second chance.

Or save before you hack...

Or back out of the computer when you have 1 try left.

Or just "back out" before your last attempt and you get a fresh four attempts at a new puzzle.

Or get a mod that just gives you 4 choices so you can't run out of attempts.

However, most of us just backed out after the 3rd attempt.

The only "cheat" mod I had installed was one that by-passed the hacking mini game, you still needed to have the appropriate skill level to hack but you didn't have to do that awfully tedious mini game.

But yeah before I had that, back out before you "allowance" is spend.