Safecracking is an interesting hobby, and the purview of the safecrackers specilisation. The crack command is only available to thieves who have 90+ levels of covert.lockpick.safes. A set of cracking tools is needed to crack a safe. Other tools may also be required. There are different types of safes out there and they are generally hidden. Ankh-Morpork is unique in the fact that many of them are not hidden at all.
Some of the tools required include: a small mirror, drill, rubber gloves. crowbar, and a hefty hammer.
The tumbler dial safe is one of the hardest puzzle types. Many people get stuck because they aren't correctly visualizing the device. It's essentially a master lock except with 100 ticks instead of 40. The key thing is, suppose the dial is at the number 5, and you turn the dial 1 degree clockwise -- what number is the dial at now?
Anyway, here is a set of aliases that can help to crack a tumbler dial safe.
alias dc: turn dial clockwise to
alias dcc: turn dial anticlockwise to
alias dtest: dc 0;frimble Tumbler Safe Cracking;dcc 20;dcc 40;frimble 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9;dcc 60;dcc 80;dcc 0
alias dtry: dc $1$;dcc $2$;dc $3$;dcc $1$;dc $2$;dcc $3$;dc $1$;dcc $3$;dc $2$;dcc $1$;dc $3$;dcc $2$;dc $1$;open safe