-https://www.chessvariants.com/diffobjective.dir/anti-king-chess.html
+<p>
+ The antiking (represented by an upside-down king)
+ must always remain under attack.
+ It can capture pieces of its color.
+</p>
+
+<p>
+ Win by checkmating the king, or anti-mating the antiking — that is to
+ say, making it unable to move to an attacked square.
+</p>
+
+<p>In Anti-King I,</p>
+<ul>
+ <li>Pawns are Berolina: they move diagonally and capture vertically.</li>
+ <li>
+ King and Antiking can play one non-capturing knight move,
+ as long as they never moved earlier.
+ </li>
+</ul>
+
+<p>
+ <a href="https://www.chessvariants.com/diffobjective.dir/anti-king-chess.html">
+ chessvariants page.
+ </a>
+</p>
+
+<p class="author">Peter Aronson (2002).</p>