{{Infobox version
|title=Minecraft 13w21a
|image=13w21a Banner.png
|image2=Java Edition 13w21a.png
|edition=Java
|type=Snapshot
|parent=1.6.1
|date=May 23, 2013
|clienthash=c89ead145ca87737ca2d10901a4f3bc837937006
|jsonhash=fde079e7e92109831ddb7365bec0560408b4916e
|serverhash=a04b6f0349b8de64c68a9311b4eaff478e37b558
|exehash=f1e233ab374e929d0d76e568fcd7e046f8b75106
|java_manual={{wikipedia|Java version history#Java SE 6|Java SE 6|newtab=1}}
|prevparent=1.5.2
|prev=13w19a
|next=13w21b
|nextparent=1.6.2
}}<onlyinclude>

'''13w21a''' is the eighth [[snapshot]] for [[Java Edition 1.6.1]], released on May 23, 2013<ref>https://web.archive.org/web/0/https://www.mojang.com/2013/05/snapshot-13w21a/</ref><ref>https://twitter.com/Dinnerbone/status/337596332523003904</ref>.

== Additions ==
=== Mobs ===
; [[Donkey]]s, [[horse]]s and [[mule]]s
* Added a UI to control saddle/inventory/armor.
* Can be accessed by sneaking and right-clicking, or by pressing the inventory button while riding.
* Some features of the UI are specific to certain mobs:
** All three mobs have a saddle slot.
** Only horses have an armor slot.
** Donkeys and mules have an inventory of 15 slots when given a chest.

=== General ===
; [[Attribute]] system
* Started to move over various things to a [[Chunk format#Attributes|new attribute system]]:
** Item attributes using NBT data:
*** Attributes can be additive, subtractive and multiplicative using a set value.
*** Some items have default modifiers in place of previously hard-coded attributes.
*** Examples of possible changes players could make: A bow that slows the holder, a helmet that buffs health, etc.
** Entity attributes:
*** These properties can now be changed as easily as any other NBT attribute.
*** Entity speed, base health, base attack.
** Other properties like weapon damage/bow draw speed/sword swing speed are yet to follow.

; Internal chat system
* Lots of messages should be translated now that were not previously.
* Messages are now better modularized.
* Server messages can be sent by their code-defined name, allowing the client to utilize the correct translation according to their language settings.
* Color can be specifically designated, preventing leakage into further messages.

== Changes ==
=== Items ===
; [[Horse armor]]
* No longer stackable.

; [[Tool]]s
* Instead of replacing the barehanded damage ({{hp|1}}), pickaxes, shovels, axes and swords now add their damage onto the barehanded damage.

=== General ===
; [[Resource pack]]s
* Lots of work towards a new resource pack system, but not finished yet.
** Currently still compatible with texture packs.

== Fixes ==
{{fixes|fixedin=13w21a|prefix=Snapshot
|;old
|1497|Damaged anvils do not show damage in inventory or item frame.
|;dev
|13626|XP Bar shows up in creative.
|13640|Hay bales do not burn when set on fire.
|13662|XP, health, and hunger bar are buggy with horses.
|13770|Using a horse spawn egg on a horse works only when riding the horse.
|13852|Can't throw enderpearls while mounting a horse.
|14220|Player appearance not updating in multiplayer (armor, tools).
|14417|No way to remove armor or saddles off a horse.
|14422|Horse name tag is shown while riding.
|15138|Sides of cauldron has compass texture after placing compass in item frame.
|15201|Bottom part of some types of horses-harness is misplaced.
|;previous
|15416|Selected item disappears when armor breaks.
}}</onlyinclude>

== Trivia ==
* This is the first time a snapshot was released on [[wikipedia:World Turtle Day|World Turtle Day]].

== References ==
{{Reflist}}

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

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