Editing En passant (section)

==Chess problems==
The ''en passant'' capture is often used as a theme in [[chess problem]]s. According to Kenneth S. Howard, "En passant pawn captures frequently produce striking effects in the opening and closing of lines, both for white and black."<ref name="Howard">{{citation |last=Howard |first=Kenneth S. |year=1961 |title=How to Solve Chess Problems |edition=2nd |publisher=Dover |isbn=978-0-486-20748-3 |url=https://books.google.com/books?id=TAr0VrN-G3MC&q=%22en+passant%22+chess&pg=PA106 |access-date=2009-11-30 |archive-date=2023-04-06 |archive-url=https://web.archive.org/web/20230406050809/https://books.google.com/books?id=TAr0VrN-G3MC&q=%22en+passant%22+chess&pg=PA106 |url-status=live }}</ref>{{rp|106}} By [[retrograde analysis]] convention, a pawn may be captured ''en passant'' only if it can be proven to have advanced two squares on the previous move.

{{Chess diagram  
| tright
| Kenneth S. Howard, 1938
|bl|  |  |  |  |nd|  |  
|  |  |  |pd|pd|pd|  |  
|  |nl|pd|  |kd|  |  |nl
|  |  |pl|  |pl|  |  |  
|  |  |pd|  |pd|  |  |pd
|  |  |  |  |  |  |bl|  
|  |  |  |pl|  |pl|  |  
|ql|  |  |  |rl|  |kl|
| White to play and mate in three 
}}
In the diagrammed 1938 composition by Howard, the {{chessprobgloss|key}} 
:'''1. d4{{chesspunc|!}}''' 
introduces the threat 2.d5+ cxd5 3.Bxd5#. Black can capture the d4-pawn ''en passant'' in either of two ways:
:'''1... exd3 e.p.''' 
shifting the e4-pawn from the e- to the d-file, preventing an ''en passant'' capture after White plays 2.f4. To stop the threat of 3.f5#, Black can advance 2...f5, but this allows White to play 3.exf6 e.p.# due to the decisive opening of the {{nowrap|e-file}}.

Or Black can play
:'''1... cxd3 e.p.'''
and now White exploits the newly opened a2–g8 diagonal with 2.Qa2+ d5 3.cxd6 e.p.#.
{{clear}}

{{Chess diagram  
| tright
| O. Sommerfeldt, 1902
|  |  |  |  |  |  |  |  
|  |bd|  |  |  |qd|  |  
|bl|  |  |  |  |  |  |  
|  |  |  |  |  |  |pd|  
|  |rl|  |  |pd|kd|pl|pd
|  |pd|  |  |  |  |  |pl
|  |ql|  |pl|  |  |kl|  
|  |  |  |  |  |  |  |
| White to play and mate in two
}}

The diagrammed composition by Sommerfeldt<ref>[http://timkr.home.xs4all.nl/chess2/diary_12.htm Open chess diary] {{Webarchive|url=https://web.archive.org/web/20150318004936/http://timkr.home.xs4all.nl/chess2/diary_12.htm |date=2015-03-18 }} by Tim Krabbé – #234</ref> shows the effect of [[Pin (chess)|pins]] on ''en passant'' captures.

The key 
:'''1. d4!''' 
threatens 2.Qf2#. The moves of the black e-pawn are restricted in an unusual manner. The ''en passant'' capture 1...exd3 e.p.+ is illegal (it exposes Black’s king to check), but 
:'''1... e3+''' 
is legal. This, however, removes the black king's access to e3, allowing 
:'''2. d5#'''
{{clear}}