clarify combat rules

DR is clarified as stacking in the same way as everything else.

Weapon knacks are explicitly stated as not counting towards a PC's total knacks.

Dropping a weapon without attacking reduces initiative.

combat.tex

@@ -41,7 +41,7 @@
 
 	Speaking & 2 \\\hline
 
-	-- \textbf{Other} & \\\hline
+	-- \textbf{Magic} & \\\hline
 
 	Use magic item & 8 \\
 
@@ -192,8 +192,9 @@ Each weapon has a \gls{weightrating}, just like any item.
 For every point a weapon's \gls{weightrating} exceeds its wielder's Strength Bonus, the wielder gains 1 Encumbrance, which subtracts from the character's Effective Speed as they move slower and swings the weapon slower.
 Weapons held in only one hand add +2 to their \gls{weightrating}.
 
-Finally, some weapons also have an in-built `Knack' -- a special ability they allow the wielder to use.
-See Chapter \ref{knacks} for a full list of Knacks.
+Finally, some weapons also have an in-built `knack' -- a special ability they allow the wielder to use.
+These weapon knacks are not counted towards the character's total knacks, except for the purposes of the weapon's knack.
+See Chapter \ref{knacks} for a full list of knacks.
 
 \end{multicols}
 
@@ -377,6 +378,11 @@ Armour also inflicts Fatigue very quickly, as mentioned above. Wearing armour in
 
 \index{Combat!Perfect Strikes}Rolling a \gls{natural} `12' in combat, i.e. rolling two 6's, means the roll was a Perfect Strike. A Perfect Strike is guaranteed to hit even if it doesn't reach the opponent's \gls{tn}, it ignores both Partial and Complete armour (covered below) and it grants +2 Damage.
 
+\subsection{Stacking Armour}
+
+Characters gain \gls{dr} from armour, but animals can gain  \gls{dr} from a thick hide, while the undead gain \gls{dr} from having less need of a functioning body.
+When multiple types of Damage stack, the second counts for only half (rounded up), and any tertiary damage types count for a quarter, and so on.
+
 \end{multicols}
 
 \section{Advanced Combat}
@@ -705,6 +711,10 @@ Anyone can choose to attack someone while ignoring their opponent's weapon's bon
 
 \index{Combat!Drawing Weapons}Drawing a weapon costs 2 Initiative if it is placed in an easy place to draw, like a scabbard on the side of a belt. If a character holds weapons on the back or in a bag, it costs 8 Initiative to remove them. If a knife's stuffed inside a pack, the \gls{gm} may stipulate a number of \glspl{round} required to draw the weapon.
 
+\subsubsection{Dropping Weapons}
+
+Dropping a weapon is free, but if the character has not made an attack then the weapon's Initiative Bonus is lost.
+
 \subsubsection{Flanking}\label{flank}
 
 Attacks from someone's anterior side gain a +2 Bonus.
@@ -960,7 +970,6 @@ His Sneak Attack gives him +4 to strike the ogre - which he does - and +2 Damage
 	\end{tcolorbox}
 }
 
-
 \begin{multicols}{2}
 
 \noindent

knacks.tex

@@ -190,11 +190,15 @@ The character is particularly adept at casting spells quickly, and therefore in
 
 \subsubsection{Chosen Enemy}
 
-The character has a burning hatred for a particular race of creature. The character gains a -2 penalty when interacting socially with such creatures and a +1 when performing actions such as tracking them, attacking them or intimidating them.
+The character has a burning hatred for a particular race of creature.
+The character gains a -2 penalty when interacting socially with such creatures and a +1 when performing actions such as tracking them, attacking them or intimidating them.
+The only combat bonus gained is for attack.
 
 For each Knack the player has, they may select a new chosen enemy, so those with a total of 3 Knacks may select 3 chosen enemies. Those enemies may be chosen at any time, including long after a new Knack as been bought.
 
-Possible enemies include: Forest Creatures, Behemoths, any humanoid race (e.g. Dwarves, Humans, et c.), Goblins, Underground Creatures and Undead.\footnote{Chosen enemies never stack, so an undead hobgoblin does \emph{not} stack bonuses.}
+Possible enemies include: Forest Creatures, bandits, magic users, any humanoid race (e.g. Dwarves, Humans, et c.), Underground Creatures and Undead.
+Chosen enemies never stack, so an undead forest creature only counts as one chosen enemy.
+\footnote{If your campaign includes nura, you can gain chosen enemies such as `goblinoids' (including all sentient nura), and `nura beasts'.}
 
 \subsubsection{Fast Healer}