What does it mean to "brick" your phone? I'm considering unlocking the bootloader on my Verizon Galaxy S3 (SCH-I535).  However, a guide I was reading made this statement:


  Once you have unlocked your phone’s bootloader using this app, you must not receive any over-the-air (OTA) updates or via Samsung Kies. Doing so will result in bricking your phone.


I understand that bricking a phone means rendering it unusable, but does this also mean unrecoverable?  When a phone is "bricked", does that mean it is virtually impossible to restore it to a working state?

I'm a little concerned about the risk if that is the case.
The term "brick" usually refers to the stone, which means: "device can only be used as paper-weight". Taken literally, there's no way to "unbrick".



However, you also find terms like "hard-brick" and "soft-brick" used, which makes the term "brick" less absolute: A soft-brick is something you easily can recover from (count it as a "temporary paper-weight"), mostly by software-based solutions (e.g. re-flash your phone) -- while a "hard-brick" is rather meant in the way the original term points to.

Still, technically spoken, even a "hard-bricked" device could be "unbricked" -- but mostly this is more expensive then getting a new device.

As for the warranty declaration you quoted: For a normal user, it's almost impossible to (hard-) brick his device. Even when flashing a custom ROM, this can rarely happen, as there are many security-layers involved. Almost always you can boot your device into some fall-back mode where it is at least recognized by some "flashing software", so you could simply flash another/the original firmware back. Which means, the risk you are taking is to "soft-brick" your device1. A "hard-brick" is quite unlikely with "normal operations" like rooting or flashing custom ROMs.

See also:


Wikipedia: Brick
RootzWiki: Brick


1 I just learned: "Unless you've got a Samsung device and used the software recommended by Samsung". So better don't use Kies etc., but rather Odin, just to give an example.