Patches

Patches are updates to the game that fix known bugs, glitches, or exploits within the game, and often add new features or balance changes to items, levels, or other game elements.

Although each patch is usually paired with notes detailing what has been altered, some alterations are not mentioned. These undocumented changes rely on the community to notice their existance and therefore report them to others. As such, the exact date of undocumented change implementation will be an estimate.

2011

 * July 1
 * May 26
 * May 20
 * May 12
 * May 10
 * May 6
 * April 29
 * April 22
 * April 21
 * April 19

2011

 * May 26
 * May 20
 * May 17
 * May 12

Full list of Portal patches
{{Columns-list|2|

2011

 * March 2

2010

 * November 12
 * August 17
 * July 21
 * June 15
 * June 3
 * May 27
 * May 25
 * May 15
 * May 13
 * March 3
 * March 1 (ARG)

2009

 * June 23
 * February 20
 * February 17

2008

 * June 10
 * January 26

2007
}}
 * November 27
 * October 30

2005

 * April 19
 * April 5
 * February 22
 * February 1