Workign at B&N, I never had to pay. There was an expected amount that your till may be over/under due to the fact that we never counted money at the end of our shift, but used a scale that weighed the money and got a count from that. At the end of our shifts we were required to balnace out our tills, meanign bring them back to starting amount for the next cashier (each drawer started out with $125). When it was time for us to leave, our manager would come and pull you, do a register report, and you carried your drawer to the back to do a count and balance it. All overage money (money taken in from customers on your shift) was placed into an envelope and depositied into the safe.
And no worries about the scale being off to count our money. You entered what demonination you were counting and the scale would adjust. I had 4 dimes in the dime change cup once, and when I placed the cup on the scale it counted correctly. Never, was there ever an issue with the scale.
At B&N, it was policy, again that if you were over/under by a small amount <$1 it was to be expected. $1-$5 you were given a reprieve and told to watch your cash handling next time around (i.e. don't become distracted while counting change back). Anything over $5 and you got written up. I once forgot to include a roll of dimes in my count and got written up (I was off my exactly $5). First offense you were given a write up, second time a remediation plan, third time you were taken away from handling cash/doing register or if a pattern continued, then you would be fired.
But never were we ever required to pay.
Also, shortly before I left B&N, our managers decided to not pull tills after an individual shift, but to do it at the end of the day. So that meant that often, there would be two or three people on one drawer during the course of the day. At first many of us were worried about what would happen if at the end of the day if the drawer was off, however the managers had it worked to perfection. I know that I was never off (with the exception of that $5 that one time). The managers were suspecting someone of bad cash handling, so they would always put them on my drawer after my shift to see what they were doing.
Now, one day I'll tell you the story of the Head Cashier that was caught stealign money from not only the registers, but the safe. I warned my managers that he was not the right fot for the position, but it took a good 6 months after I left for him to get caught. And did he ever get caught, he was escorted out of the store by the police. And yes, I have annimosity towards him, because before he became HC he threw me under the bus to one of our old managers.