make TN gls entry

rules/actions_basic.tex

@@ -5,7 +5,7 @@ The dice roll remains fixed, so anyone attempting the same action receives the s
 
 \begin{enumerate}
   \item
-  The \gls{gm} states the TN:
+  The \gls{gm} states the \gls{tn}:
 
   \begin{itemize}
     \item
@@ -29,11 +29,11 @@ The dice roll remains fixed, so anyone attempting the same action receives the s
   The \gls{gm} interprets the results:
   \begin{itemize}
     \item
-    If the roll exceeds the TN, the action was a success.
+    If the roll exceeds the \gls{tn}, the action was a success.
     \item
-    If the roll falls below the TN, the action fails, and the danger occurs.
+    If the roll falls below the \gls{tn}, the action fails, and the danger occurs.
     \item
-    If the roll equals the TN, the result is a \emph{tie}.
+    If the roll equals the \gls{tn}, the result is a \emph{tie}.
     If success and failure conditions could occur at the same time, the character may choose to accept both, or neither.
     Otherwise, the result is a partial success.
     \end{itemize}

rules/actions_resisted.tex

@@ -2,5 +2,5 @@
 
 \begin{itemize}
   \item
-  The player rolls at TN 7 plus the opponent's Bonuses.
+  The player rolls at \gls{tn} 7 plus the opponent's Bonuses.
 \end{itemize}