How to quit minecraft without saving?

End the process in the command prompt. This worked back when it was in beta.

uhm ?! end task ? or just copy/paste save file everytime ?

make a backup(copy) of your world before testing it, then copy the backup over the blown up world to test again.
end task would only work if you beat minecraft to saving the chunk changes in the savefile

mod, not sure if there is any. but you can save it and then put it back manually. not sure how, but server admins know that stuff.

unplug your computer, or if you're badass enough, just smash it with a durable and big blunt object

alt f4?

Where is your win EVE Online: Inferno ?

Maybe you should try another ways to kill the player (lawa, arrows, fireballs). And also you definetly must try last minecraft snapshot. The new block for adventure map creators can change spawnpoint with a pressure plate.

No mod?

alt f4 use to work, however MC autosaves now. Found that out the hard way :<

Ctrl+Shift+Esc, find minecraft, press "end process"

Why don't you just make a backup?

Delete system32.

control alt delete or create backup

Minecraft saves all the time (you couldn't leave an area and come back if it didn't save your changes). The only solution is to back up your save files.

Making a backup is your best bet. Minecraft saves all the time, even with OptiFine

K thx everyone for your replies apparently backing up the map is the only way.

Why not put the switch in last, that way you won't blow it up prematurely.