I can try being helpful, but without your code, it is not that easy...
That said, are you sure the game tag is not <game name="chess" players="3" /> (with a slash instead of a backslash)? In that case it doesn't need a closing tag. The / before the closing angle bracket means that the tag is empty and should be treated as both an opening and a closing tag. As far as an XML parser is concerned <game name="chess" players="3" /> is equivalent to <game name="chess" players="3"></game>, so the XML you are generating should be OK (did you try checking it with an XML parser?).
Are you posting in the right place? Check out Where do I post X? to know for sure.
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
Want more info? How to link
or How to display code and escape characters
are good places to start.