[iagno] Rework help Rules page.

[Arnaud B. <arnaudb src gnome org>]

commit 56c6d923299c6940d59b6a3f00c1634293bbb5bd
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Sat Feb 1 17:52:14 2020 +0100

    Rework help Rules page.

 help/C/rules.page | 86 +++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 55 insertions(+), 31 deletions(-)
---
diff --git a/help/C/rules.page b/help/C/rules.page
index b37cba7..8619daf 100644
--- a/help/C/rules.page
+++ b/help/C/rules.page
@@ -21,47 +21,71 @@
       <email its:translate="no">me stevepdp org</email>
       <years>2015</years>
     </credit>
-    <credit type="editor">
+    <credit type="editor copyright">
       <name>Arnaud Bonatti</name>
       <email>arnaud bonatti gmail com</email>
       <years>2020</years>
     </credit>
 
-    <desc></desc>
+    <license>
+      <p>Creative Commons Share Alike 3.0</p>
+    </license>
   </info>
 
   <title>Rules</title>
 
-  <p>The object of the game is to flip as many of the opponent tiles while blocking your opponent from 
flipping your tiles. In order to flip a tile, you must first trap it between two of your tiles, horizontally, 
vertically or diagonally.</p>
-  <steps>
-    <item><p>
-      The game begins with four pieces, two light and two dark, placed in the center of the board.
-    </p></item>
-    <item><p><em>Dark</em> goes first.</p></item>
-    <item><p><em>Dark</em> places a tile on the board in such a way that it traps white tiles between two of 
the dark tiles.</p>
+  <p><em>Classic Reversi</em> and <em>Reverse Reversi</em> are boardgames opposing two players, called 
<em>Dark</em> and <em>Light</em>. Both games are using the same rules; only the end goal differs between 
them: in <em>Classic Reversi</em>, the goal is to finish with <em>more</em> pieces than the opponent; while 
in <em>Reverse Reversi</em>, it is to finish with <em>less</em> pieces.</p>
+
+  <p>Both are played with pieces that are dark on one side and light on the other. <em>Dark</em> and 
<em>Light</em> play one after each other by adding on an empty tile a new piece of their color, trapping at 
least one opponent row of pieces; when pieces are captured that way, they are turned over to join the 
capturing player's forces.</p>
+
+  <section id="game-start">
+    <title>Game start</title>
+
+    <p>Games from the reversi game family are usually played on an 8 by 8 board. The game begins with four 
pieces, two light and two dark, placed on the four central tiles of the board.</p>
+
+    <p><app>Reversi</app> uses by default the most usual start position for the reversi game family, that is 
displayed on the following figure; but it also allows you to <link xref="start-position">vary start 
position</link> if you prefer.</p>
+
+    <table>
+      <tr>
+        <td>
+          <media type="image" src="figures/usual-start.png" width="200" its:translate="no">
+            <p its:translate="yes">Usual start position: light-dark, dark-light</p>
+          </media>
+        </td>
+      </tr>
+      <tr>
+        <td>
+          <p><em>The usual start position</em></p>
+        </td>
+      </tr>
+    </table>
+
+    <p><em>Dark</em> goes first.</p>
+  </section>
+
+  <section id="during-game">
+    <title>During the game</title>
+
+    <p>One player after the other –<em>Dark</em> playing first– places a tile of its color on the board in 
such a way that at least one row of opponent tiles is trapped between the newly placed piece and an already 
placed one of the same color.</p>
+
     <note><p>This placement can be horizontal, vertical or diagonal.
     </p></note>
-    <p>
-     When the dark tile is placed, the light tiles between the newly placed dark tile and another dark tile 
are flipped over and become part of the dark forces.
-    </p>
-    </item>
-    <item><p>The players alternate turns until no more legal moves can be made by either player.  At this 
point the game is over. The end of the game often results in a full board.</p></item>
-    <item><p>The winner is the the player with the most pieces of his color on the board.</p></item>
-  </steps>
-
-  <table>
-    <tr>
-      <td>
-        <media type="image" src="figures/usual-start.png" width="200" its:translate="no">
-          <p its:translate="yes">Usual start position: light-dark, dark-light</p>
-        </media>
-      </td>
-    </tr>
-    <tr>
-      <td>
-        <p><em>The usual start position</em></p>
-      </td>
-    </tr>
-  </table>
+
+    <p>When the tile is placed, the row of tiles between the newly placed tile and the other is flipped 
over, taking the players color. If multiple rows of tiles are trapped that way, they are all flipped over.</p>
+
+    <p>If there is no possible moves in a turn, the player has to pass. A player cannot pass a turn if there 
is a possible move. If both players cannot move, notably when the board is full, the game is over.</p>
+  </section>
+
+  <section id="game-end">
+    <title>End of game</title>
+
+    <p>The players alternate turns until no more legal moves can be made by either player. At this point the 
game is over.</p>
+
+    <p>The end of the game often results in a full board, but not necessarily. In either way, it is the 
number of pieces that will matter to decide who wins.</p>
+
+    <p>If you are playing <em>Classic Reversi</em>, the winner is the player with the <em>most</em> pieces 
of his color on the board; if you are in a <em>Reverse Reversi</em> game, it is the opposite: the winner is 
the player with the <em>least</em> pieces on the board.</p>
+
+    <p>If there is the same number of dark and light tiles, the game is declared a draw.</p>
+  </section>
 
 </page>