pre-session updates

src/pages/rules/magic.md

@@ -40,9 +40,10 @@ Ritual spells may be cast by performing the ritual as described.
 ### Spell Effects
 
 -   Some spells affect multiple targets, either by area or by Hit Dice total. If the spell doesn't say how to select the targets, the referee decides.
--   Some spells require the caster to concentrate to maintain the spell's effect.
-    -   Performing any other action causes concentration to end.
-    -   When distracted (ex: attacked) while concentrating, the spellcaster must make a Willpower check (highest of CHA or CON) or the spell ends.
+-   Some spells require **concentration**.
+    -   These spells require the caster's focus to maintain the spell's effect.
+    -   Performing any other action (moving or attacking) causes concentration to end.
+    -   When distracted (ex: damaged by a spell or weapon) while concentrating, the spellcaster must make a Willpower check (highest of CHA or CON), with a penalty of 1/2 the damage inflicted (to a max of -4), or the spell ends.
 -   Multiple spells cannot increase the same ability (e.g. bonuses to attack rolls, AC, damage rolls, saving throws, etc.).
     -   Spells that affect different abilities can be combined.
     -   Spells can also be combined with the effects of magical items.
@@ -60,7 +61,7 @@ New spells may be found and learned (or created) via research.
 Alchemical formulas (for brewing potions and such) can be learned and used by anyone with access to the proper equipment.
 
 -   Some arcane spellcasters store learned alchemical formulae within their spellbooks.
--   The difficulty with most potions is not in the brewing, but in aquiring the ingredients (and/or the correct formula).
+-   The difficulty with most potions is not in the brewing, but in acquiring the ingredients (and/or the correct formula).
 
 ### Arcane Magic