What is the actual risk of bricking when rooting for new ROM Possible Duplicate:
  Are there any risks to rooting a device?  




I've been planning to root my HTC One S for a while now, because the HTC software is so unstable. Sometimes it crashes every day for a certain period, sometimes even multiple times a day, I did a factory reset and the problem was gone for weeks but it recently came back. It has been going clean for 3 days now so it may be another period where it keeps stable, but I cannot trust it for too long.

Now consider these facts:


I will follow every instruction that I found on this forum, Phandroid.
I have experience with linux. Not too much, but I know how the file system works and I can work with bash.
I have quite a  bit of programming experience and I'm generally pretty good with computers.


The latter two may not be so relevant to the story of rooting, but all is to say that I'm an advanced user at least, if not expert. I know how to troubleshoot and I know when I should doubt an instruction or not.

That said, taking these things into account, and considering the fact that I've never rooted a smartphone, what is the approximate real chance of me making my phone unrecoverably damaged/bricked/whatever..., If I'm careful?

I'm just asking because this thing has cost enough money and it would be quite depressing to turn it into a worthless lump of plastic and metal.
If you're careful - risk is minimal. I do say minimal because there is no 0 risk!

Let's split this in parts.

Installing custom recovery: 
Higher risk because now you're overwriting the recovery partition of the phone. If you're in the process of overwriting and your phone shuts off, the recovery part may get corrupted. Will your phone brick though? Maybe, depending if the boot partition may also be affected. But, since your phone uses fastboot, the risk decreases.

Rooting:
Usually the least risk operation of all, since you're pushing files to the device. If it messes up, chances are factory resetting will let you start again.

Now you've got custom recovery set up and want to try out a custom ROM
Risk  - Less than installing recovery if you choose a ROM for your device. Custom ROMS usually just copy the OS onto the phone. This should not touch the recovery partition. This means that should it fail and the phone does not boot into an OS, you can still use the recovery partition to restore a backup, retry the install or try another ROM. This may change though, if you install a non One S ROM, as most ROM zips have a hardcoded partition when they modify.

So remember to read the instructions thoroughly, make sure your battery is fully charged when doing this, back up your current OS after you install custom recovery and make sure you install the ROM that is made for your device.