{{Infobox version
|title=Minecraft 12w39b
|image=SP 12w39a image.png
|image2=Java Edition 12w39b.png
|edition=java
|type=Snapshot
|parent=1.4.2
|date=September 28, 2012
|clientdl=[https://vault.omniarchive.uk/archive/java/client-release/1.4/pre/12w39b.jar Client] ([https://archive.org/download/Minecraft-JSONs/12w39b.json .json])
|serverdl=[https://vault.omniarchive.uk/archive/java/server-release/1.4/pre/12w39b.jar Server]
|exedl=[https://vault.omniarchive.uk/archive/java/server-release/1.4/pre/12w39b.exe .exe]
[[Category:Versions using legacy download site]]
|prevparent=1.3.2
|prev=12w39a
|next=12w40a
|nextparent=1.4.4
}}<onlyinclude>

'''12w39b''' is the ninth [[snapshot]] for [[Java Edition 1.4.2]], released on September 28, 2012<ref>https://twitter.com/Dinnerbone/status/251683603593957376</ref> to fix some of the bugs and crashes in the [[12w39a]] snapshot.

== Additions ==
=== Blocks ===
; [[Mob spawner]]s
* More options to customize spawners.
* Can now have their range and maximum spawn limit customized.

=== Items ===
; Custom [[potion]]s
* Only available by editing in with a world editor.
* Players can create potions with multiple effects.

=== Command format ===
; {{cmd|xp}}
* Added a command variable to the command.
** Use <code>L</code> after number to represent number of levels, not number of xp.

; [[Target selector]]s
* Added command block arguments.
** Added <code>l</code> and <code>lm</code> arguments for indicating players with a maximum level, and minimum level, respectively.
** Added <code>rm</code> argument for indicating the minimum range to which players are affected.

== Fixes ==
; 7 bugs fixed
* Fixed block placement issues with lighting.<ref>{{tweet|dinnerbone|251685433568800768}}</ref>
* Game performance is now better from before.
* Fixed "Bottomless Pit" preset.
* Jack o' lantern emitting stronger light from the wrong face fixed.
* Fixed the witch's texture being weird.
* Partially fixed Nether lag by making the server do some of what used to be the client's work and increasing chunk load time slightly.<ref>{{tweet|dinnerbone|251623433505476608}}</ref>
* Fixed some lighting bugs related to upside down slabs and stairs and farmland.</onlyinclude>

== References ==
{{reflist}}

== Navigation ==
{{Navbox Java Edition versions|1.0}}

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