diff --git a/dungeonsheets/character.py b/dungeonsheets/character.py
index 3b14de3..d752bc8 100644
--- a/dungeonsheets/character.py
+++ b/dungeonsheets/character.py
@@ -69,83 +69,6 @@ multiclass_spellslots_by_level = {
 }
 
 
-def _resolve_mechanic(mechanic, SuperClass, warning_message=None):
-    """Take a raw entry in a character sheet and turn it into a usable object.
-
-    Eg: spells can be defined in many ways. This function accepts all
-    of those options and returns an actual *Spell* class that can be
-    used by a character::
-
-        >>> _resolve_mechanic("mage_hand", SuperClass=spells.Spell)
-
-        >>> _resolve_mechanic("mage_hand", SuperClass=None)
-
-        >>> from dungeonsheets import spells
-        >>> class MySpell(spells.Spell): pass
-        >>> _resolve_mechanic(MySpell, SuperClass=spells.Spell)
-
-        >>> _resolve_mechanic("hocus pocus", SuperClass=spells.Spell)
-
-    The acceptable entries for *mechanic*, in priority order, are:
-      1. A subclass of *SuperClass*
-      2. A string with the name of defined content
-      3. The name of an unknown spell (creates generic object using *factory*)
-
-    *SuperClass* can be ``None`` to match any class, however this will
-    raise an exception if more than one content type has this
-    name. For example, "shield" can refer to both the armor or the
-    spell, so ``_resolve_mechanic("shield")`` will raise an exception.
-
-    Parameters
-    ==========
-    mechanic : str, type
-      The thing to be resolved, either a string with the name of the
-      mechanic, or a subclass of *ParentClass* describing the
-      mechanic.
-    SuperClass : type
-      Class to determine whether *mechanic* should just be allowed
-      through as is.
-    error_message : str, optional
-      A string whose ``str.format()`` method (receiving one positional
-      argument *mechanic*) will be used for displaying a warning when an
-      unknown mechanic is resolved. If omitted, no warning will be
-      displayed.
-
-    Returns
-    =======
-    Mechanic
-      A class representing the resolved game mechanic. This will
-      likely be a subclass of *SuperClass* if the other parameters are
-      well behaved, but this is not enforced.
-
-    """
-    is_already_resolved = isinstance(mechanic, type) and issubclass(
-        mechanic, SuperClass
-    )
-    if is_already_resolved:
-        Mechanic = mechanic
-    else:
-        try:
-            # Retrieve pre-defined mechanic
-            valid_classes = [SuperClass] if SuperClass is not None else []
-            Mechanic = find_content(mechanic, valid_classes=valid_classes)
-        except AttributeError:
-            # No pre-defined mechanic available
-            if warning_message is not None:
-                # Emit the warning
-                msg = warning_message.format(mechanic)
-                warnings.warn(msg)
-            else:
-                # Create a generic message so we can make a docstring later.
-                msg = f'Mechanic "{mechanic}" not defined. Please add it.'
-            # Create generic mechanic from the factory
-            class_name = "".join([s.title() for s in mechanic.split("_")])
-            mechanic_name = mechanic.replace("_", " ").title()
-            attrs = {"name": mechanic_name, "__doc__": msg, "source": "Unknown"}
-            Mechanic = type(class_name, (SuperClass,), attrs)
-    return Mechanic
-
-
 class Character(Entity):
     """A generic player character."""
 
@@ -628,7 +551,7 @@ class Character(Entity):
                         f'Magic Item "{mitem}" not defined. '
                         "Please add it to ``magic_items.py``"
                     )
-                    ThisMagicItem = _resolve_mechanic(
+                    ThisMagicItem = self._resolve_mechanic(
                         mechanic=mitem,
                         SuperClass=magic_items.MagicItem,
                         warning_message=msg,
@@ -639,7 +562,7 @@ class Character(Entity):
                 msg = 'Magic Item "{}" not defined. Please add it to ``weapons.py``'
                 wps = set(
                     [
-                        _resolve_mechanic(
+                        self._resolve_mechanic(
                             w, SuperClass=weapons.Weapon, warning_message=msg
                         )
                         for w in val
@@ -660,7 +583,7 @@ class Character(Entity):
                 _features = []
                 for f in val:
                     msg = 'Feature "{}" not defined. Please add it to ``features.py``'
-                    ThisFeature = _resolve_mechanic(
+                    ThisFeature = self._resolve_mechanic(
                         mechanic=f,
                         SuperClass=features.Feature,
                         warning_message=msg,
@@ -672,7 +595,7 @@ class Character(Entity):
                 _spells = []
                 for spell_name in val:
                     msg = 'Spell "{}" not defined. Please add it to ``spells.py``'
-                    ThisSpell = _resolve_mechanic(
+                    ThisSpell = self._resolve_mechanic(
                         mechanic=spell_name,
                         SuperClass=spells.Spell,
                         warning_message=msg,
@@ -695,7 +618,7 @@ class Character(Entity):
                             "Infusion '{}' not defined. Please add it to"
                             " ``infusions.py``"
                         )
-                        ThisInfusion = _resolve_mechanic(
+                        ThisInfusion = self._resolve_mechanic(
                             mechanic=infusion_name,
                             SuperClass=infusions.Infusion,
                             warning_message=msg,
@@ -767,6 +690,14 @@ class Character(Entity):
         final_text += "."
         return final_text
 
+    @proficiencies_text.setter
+    def proficiencies_text(self, val):
+        try:
+            profs = profiencies_text.split(",")
+        except AttributeError:
+            profs = proficiencies_text
+        self._proficiencies_text = profs
+
     @property
     def features_text(self):
         s = "\n\n--".join(
@@ -804,7 +735,7 @@ class Character(Entity):
                 new_armor = new_armor
             else:
                 msg = 'Unnown armor "{}". Please add it to ``armor.py``.'
-                NewArmor = _resolve_mechanic(
+                NewArmor = self._resolve_mechanic(
                     mechanic=new_armor,
                     SuperClass=armor.Armor,
                     warning_message=msg,
@@ -823,11 +754,8 @@ class Character(Entity):
 
         """
         if shield not in ("", "None", None):
-            try:
-                NewShield = find_content(shield, valid_classes=[armor.Shield])
-            except AttributeError:
-                # Not a string, so just treat it as Armor
-                NewShield = shield
+            msg = 'Unknown shield "{}". Please ad it to ``shields.py``.'
+            NewShield = self._resolve_mechanic(shield, SuperClass=armor.Shield, warning_message=msg)
             self.shield = NewShield()
 
     def wield_weapon(self, weapon):
@@ -840,15 +768,12 @@ class Character(Entity):
 
         """
         # Retrieve the weapon class from the weapons module
-        if isinstance(weapon, weapons.Weapon):
-            ThisWeapon = type(weapon)
-        else:
-            msg = 'Unknown weapon "{}". Please add it to ``weapons.py``.'
-            ThisWeapon = _resolve_mechanic(
-                mechanic=weapon,
-                SuperClass=weapons.Weapon,
-                warning_message=msg,
-            )
+        msg = 'Unknown weapon "{}". Please add it to ``weapons.py``.'
+        ThisWeapon = self._resolve_mechanic(
+            mechanic=weapon,
+            SuperClass=weapons.Weapon,
+            warning_message=msg,
+        )
         # Save it to the array
         self._weapons.append(ThisWeapon(wielder=self))
 
diff --git a/dungeonsheets/classes/druid.py b/dungeonsheets/classes/druid.py
index 0a6fb93..3482bec 100644
--- a/dungeonsheets/classes/druid.py
+++ b/dungeonsheets/classes/druid.py
@@ -274,7 +274,7 @@ class Druid(CharClass):
                 try:
                     NewMonster = find_content(shape, valid_classes=[monsters.Monster])
                     new_shape = NewMonster()
-                except AttributeError:
+                except exceptions.ContentNotFound:
                     msg = (
                         f"Wild shape '{shape}' not found. Please add it to"
                         " ``monsters.py``"
diff --git a/dungeonsheets/content_registry.py b/dungeonsheets/content_registry.py
index 0751029..0c55969 100644
--- a/dungeonsheets/content_registry.py
+++ b/dungeonsheets/content_registry.py
@@ -13,6 +13,7 @@ from dungeonsheets import (
     infusions,
     magic_items,
     features,
+    exceptions,
 )
 
 
@@ -38,7 +39,11 @@ class ContentRegistry:
 
         """
         # Come up with several options
-        name = name.strip()
+        try:
+            name = name.strip()
+        except AttributeError as e:
+            # Probably not a string
+            raise ValueError('content "%s" is not a valid identifier string.' % name)
         # check for +X weapons, armor, shields
         bonus = 0
         for i in range(1, 11):
@@ -72,9 +77,9 @@ class ContentRegistry:
             found_attrs = [attr for attr, v in zip(found_attrs, is_valid) if v]
         # Check that we found a valid, unique attribute
         if len(found_attrs) == 0:
-            raise AttributeError(f"Modules {self.modules} have no attribute {name}")
+            raise exceptions.ContentNotFound(f"Modules {self.modules} have no attribute {name}")
         elif len(found_attrs) > 1:
-            raise RuntimeError(f"Found multiple content entries for {name}")
+            raise exceptions.AmbiguousContent(f"Found multiple content entries for {name}")
         else:
             attr = found_attrs[0]
         # Apply weapon/etc. bonuses
@@ -100,7 +105,7 @@ default_content_registry.add_module(magic_items)
 default_content_registry.add_module(features)
 
 
-def find_content(name: str, valid_classes: Optional[List]):
+def find_content(name: str, valid_classes: Optional[List] = None):
     """Find content from a previously registered module.
 
     Parameters
diff --git a/dungeonsheets/entity.py b/dungeonsheets/entity.py
index a33b6da..763c8e0 100644
--- a/dungeonsheets/entity.py
+++ b/dungeonsheets/entity.py
@@ -1,6 +1,9 @@
 from dungeonsheets.stats import Ability, ArmorClass, Initiative, Speed, Skill
 from abc import ABC
 import os
+import warnings
+
+from dungeonsheets.content_registry import find_content
 
 
 def read(fname):
@@ -109,4 +112,83 @@ class Entity(ABC):
                 self.medicine, self.nature, self.perception,
                 self.performance, self.persuasion, self.religion,
                 self.sleight_of_hand, self.stealth, self.survival,]
-    
+
+    @staticmethod
+    def _resolve_mechanic(mechanic, SuperClass, warning_message=None):
+        """Take a raw entry in a character sheet and turn it into a usable object.
+
+        Eg: spells can be defined in many ways. This function accepts all
+        of those options and returns an actual *Spell* class that can be
+        used by a character::
+
+            >>> _resolve_mechanic("mage_hand", SuperClass=spells.Spell)
+
+            >>> _resolve_mechanic("mage_hand", SuperClass=None)
+
+            >>> from dungeonsheets import spells
+            >>> class MySpell(spells.Spell): pass
+            >>> _resolve_mechanic(MySpell, SuperClass=spells.Spell)
+
+            >>> _resolve_mechanic("hocus pocus", SuperClass=spells.Spell)
+
+        The acceptable entries for *mechanic*, in priority order, are:
+          1. A subclass of *SuperClass*
+          2. A string with the name of defined content
+          3. The name of an unknown spell (creates generic object using *factory*)
+
+        *SuperClass* can be ``None`` to match any class, however this will
+        raise an exception if more than one content type has this
+        name. For example, "shield" can refer to both the armor or the
+        spell, so ``_resolve_mechanic("shield")`` will raise an exception.
+
+        Parameters
+        ==========
+        mechanic : str, type
+          The thing to be resolved, either a string with the name of the
+          mechanic, or a subclass of *ParentClass* describing the
+          mechanic.
+        SuperClass : type
+          Class to determine whether *mechanic* should just be allowed
+          through as is.
+        error_message : str, optional
+          A string whose ``str.format()`` method (receiving one positional
+          argument *mechanic*) will be used for displaying a warning when an
+          unknown mechanic is resolved. If omitted, no warning will be
+          displayed.
+
+        Returns
+        =======
+        Mechanic
+          A class representing the resolved game mechanic. This will
+          likely be a subclass of *SuperClass* if the other parameters are
+          well behaved, but this is not enforced.
+
+        """
+        is_already_resolved = isinstance(mechanic, type) and issubclass(
+            mechanic, SuperClass
+        )
+        if is_already_resolved:
+            Mechanic = mechanic
+        elif SuperClass is not None and isinstance(mechanic, SuperClass):
+            # Has been instantiated for some reason
+            Mechanic = type(Mechanic)
+        else:
+            try:
+                # Retrieve pre-defined mechanic
+                valid_classes = [SuperClass] if SuperClass is not None else []
+                Mechanic = find_content(mechanic, valid_classes=valid_classes)
+            except ValueError:
+                # No pre-defined mechanic available
+                if warning_message is not None:
+                    # Emit the warning
+                    msg = warning_message.format(mechanic)
+                    warnings.warn(msg)
+                else:
+                    # Create a generic message so we can make a docstring later.
+                    msg = f'Mechanic "{mechanic}" not defined. Please add it.'
+                # Create generic mechanic from the factory
+                class_name = "".join([s.title() for s in mechanic.split("_")])
+                mechanic_name = mechanic.replace("_", " ").title()
+                attrs = {"name": mechanic_name, "__doc__": msg, "source": "Unknown"}
+                Mechanic = type(class_name, (SuperClass,), attrs)
+        return Mechanic
diff --git a/dungeonsheets/exceptions.py b/dungeonsheets/exceptions.py
index a8263ac..4273f93 100644
--- a/dungeonsheets/exceptions.py
+++ b/dungeonsheets/exceptions.py
@@ -28,3 +28,10 @@ class UnknownFileType(RuntimeError):
 
 class UnknownOutputFormat(RuntimeError):
     """The output format requested is not one of the known outputs."""
+
+
+class ContentNotFound(ValueError):
+    """The requested content could not be resolved."""
+
+class AmbiguousContent(ValueError):
+    """Multiple valid content entries were found."""
diff --git a/dungeonsheets/forms/spellbook_template.html b/dungeonsheets/forms/spellbook_template.html
index 46e2a46..f2daf31 100644
--- a/dungeonsheets/forms/spellbook_template.html
+++ b/dungeonsheets/forms/spellbook_template.html
@@ -96,8 +96,8 @@
   <dd>[[ spl.component_string ]]</dd>
 </dl>
 
-<block class="spell-description">
+<div class="spell-description">
   [[ spl.__doc__ | rst_to_html(top_heading_level=1) ]]
-</block>
+</div>
 
 [% endfor %]
diff --git a/dungeonsheets/make_sheets.py b/dungeonsheets/make_sheets.py
index db9e8d9..0d99941 100755
--- a/dungeonsheets/make_sheets.py
+++ b/dungeonsheets/make_sheets.py
@@ -232,7 +232,7 @@ def make_gm_sheet(
         else:
             try:
                 MyMonster = find_content(monster, valid_classes=[monsters.Monster])
-            except AttributeError:
+            except exceptions.ContentNotFound:
                 msg = f"Monster '{monster}' not found. Please add it to ``monsters.py``"
                 warnings.warn(msg)
                 continue
diff --git a/dungeonsheets/monsters/monsters.py b/dungeonsheets/monsters/monsters.py
index 0765e01..5de3bdc 100644
--- a/dungeonsheets/monsters/monsters.py
+++ b/dungeonsheets/monsters/monsters.py
@@ -3,11 +3,32 @@ shape forms.
 
 """
 
+from abc import ABCMeta
+
 
 from dungeonsheets.entity import Entity
+from dungeonsheets.spells import Spell
+from dungeonsheets.content_registry import find_content
 
 
-class Monster(Entity):
+class SpellFactory(ABCMeta):
+    """Meta class to resolve spell strings into the ``spells.Spell``.
+
+    For classes using this metaclass, the *spell* attribute, if
+    present, should be a list of spells that the entity knows. For
+    each entry on that list, anything that is not already a spell
+    class (so probably a string) will be resolved into the
+    corresponding ``spells.Spell`` class.
+    
+    """
+    def __init__(self, name, bases, attrs):
+        for idx, spell in enumerate(self.spells):
+            TheSpell = self._resolve_mechanic(spell, SuperClass=Spell)
+            self.spells[idx] = TheSpell
+
+
+class Monster(Entity, metaclass=SpellFactory):
+
     """A monster that may be encountered when adventuring."""
 
     name = "Generic Monster"
@@ -28,6 +49,7 @@ class Monster(Entity):
     burrow_speed = 0
     hp_max = 10
     hit_dice = "1d6"
+    spells = []
 
     def __init__(self):
         super(Monster, self).__init__()
diff --git a/dungeonsheets/monsters/monsters_p.py b/dungeonsheets/monsters/monsters_p.py
index ae7daca..dbbb429 100644
--- a/dungeonsheets/monsters/monsters_p.py
+++ b/dungeonsheets/monsters/monsters_p.py
@@ -362,25 +362,28 @@ class Pony(Monster):
 
 
 class Priest(Monster):
+    """Divine Eminence
+      As a bonus action, the priest can expend a spell slot to cause
+      its melee weapon attacks to magically deal an extra 10 (3d6)
+      radiant damage to a target on a hit. This benefit lasts until
+      the end of the turn. If the priest expends a spell slot of 2nd
+      level or higher, the extra damage increases by 1d6 for each
+      level above 1st.
+    Spellcasting
+      The priest is a 5th-level spellcaster. Its spellcasting ability
+      is Wisdom (spell save DC 13, +5 to hit with spell attacks). The
+      priest has the following cleric spells prepared:
+      
+      - Cantrips (at will): light, sacred flame, thaumaturgy
+      - 1st level (4 slots): cure wounds, guiding bolt, sanctuary
+      - 2nd level (3 slots): lesser restoration, spiritual weapon
+      - 3rd level (2 slots): dispel magic, spirit guardians
+      
+    Mace
+      Melee Weapon Attack: +2 to hit, reach 5 ft., one target. Hit: 3
+      (1d6) bludgeoning damage.
+    
     """
-    Divine Eminence.
-
-      As a bonus action, the priest can expend a spell slot to cause its melee weapon attacks to magically deal an extra 10 (3d6) radiant damage to a target on a hit. This benefit lasts until the end of the turn. If the priest expends a spell slot of 2nd level or higher, the extra damage increases by 1d6 for each level above 1st.
-
-    Spellcasting.
-
-      The priest is a 5th-level spellcaster. Its spellcasting ability is Wisdom (spell save DC 13, +5 to hit with spell attacks). The priest has the following cleric spells prepared:
-
-    - Cantrips (at will): light, sacred flame, thaumaturgy
-    - 1st level (4 slots): cure wounds, guiding bolt, sanctuary
-    - 2nd level (3 slots): lesser restoration, spiritual weapon
-    - 3rd level (2 slots): dispel magic, spirit guardians
-
-    Mace.
-
-      Melee Weapon Attack: +2 to hit, reach 5 ft., one target. Hit: 3 (1d6) bludgeoning damage.
-    """
-
     name = "Priest"
     description = "Medium humanoid, any alignment"
     challenge_rating = 2
diff --git a/dungeonsheets/readers.py b/dungeonsheets/readers.py
index 4e1b228..0d402e9 100644
--- a/dungeonsheets/readers.py
+++ b/dungeonsheets/readers.py
@@ -74,7 +74,6 @@ class BaseCharacterReader:
           The path to the file that will be imported.
 
         """
-        print(filename)
         self.filename = filename
 
     def __call__(self, filename):
@@ -285,7 +284,7 @@ class Roll20CharacterReader(JSONCharacterReader):
             match = prof_re.match(obj["name"])
             if match:
                 tool_profs.append(self.get_attrib(match.group(0)))
-        char_props["_proficiencies_text"] = tool_profs
+        char_props["proficiencies_text"] = tool_profs
         # Combat stats
         char_props["hp_max"] = self.as_int(self.get_attrib("hp", which="max"))
         # Equipment
@@ -531,7 +530,7 @@ class FoundryCharacterReader(JSONCharacterReader):
         tool_profs = [tool_labels[prof] for prof in tool_profs]
         custom_tool_profs = json_data["data"]["traits"]["toolProf"]["custom"]
         tool_profs.extend([s.strip() for s in custom_tool_profs.split(";")])
-        char_props["_proficiencies_text"] = tool_profs
+        char_props["proficiencies_text"] = tool_profs
         # Combat stats
         char_props["hp_max"] = self.as_int(json_data["data"]["attributes"]["hp"]["max"])
         # Equipment
diff --git a/tests/test_character.py b/tests/test_character.py
index 3a7ef8b..9cd4fd4 100755
--- a/tests/test_character.py
+++ b/tests/test_character.py
@@ -8,7 +8,6 @@ from dungeonsheets.character import (
     Character,
     Wizard,
     Druid,
-    _resolve_mechanic,
 )
 from dungeonsheets.weapons import Weapon, Shortsword
 from dungeonsheets.armor import Armor, LeatherArmor, Shield
@@ -81,21 +80,21 @@ class TestCharacter(TestCase):
 
     def test_resolve_mechanic(self):
         # Test a well defined mechanic
-        NewSpell = _resolve_mechanic("mage_hand", None)
+        NewSpell = Character._resolve_mechanic("mage_hand", None)
         self.assertTrue(issubclass(NewSpell, spells.Spell))
 
         # Test an unknown mechanic
         def new_spell(**params):
             return spells.Spell
 
-        NewSpell = _resolve_mechanic("hocus_pocus", spells.Spell)
+        NewSpell = Character._resolve_mechanic("hocus_pocus", spells.Spell)
         self.assertTrue(issubclass(NewSpell, spells.Spell))
 
         # Test direct resolution of a proper subclass
         class MySpell(spells.Spell):
             pass
 
-        NewSpell = _resolve_mechanic(MySpell, spells.Spell)
+        NewSpell = Character._resolve_mechanic(MySpell, spells.Spell)
 
     def test_wield_weapon(self):
         char = Character()
@@ -110,13 +109,13 @@ class TestCharacter(TestCase):
         self.assertEqual(sword.attack_modifier, 4)  # str + prof
         self.assertEqual(sword.damage, "1d6+2")  # str
         # Check if dexterity is used if it's higher (Finesse weapon)
-        char.weapons = []
+        char._weapons = []
         char.dexterity = 16
         char.wield_weapon("shortsword")
         sword = char.weapons[0]
         self.assertEqual(sword.attack_modifier, 5)  # dex + prof
         # Check if race weapon proficiencies are considered
-        char.weapons = []
+        char._weapons = []
         char.weapon_proficiencies = []
         char.race = race.HighElf()
         char.wield_weapon("shortsword")
diff --git a/tests/test_make_sheets.py b/tests/test_make_sheets.py
index 73ff1ca..4855df4 100644
--- a/tests/test_make_sheets.py
+++ b/tests/test_make_sheets.py
@@ -133,6 +133,7 @@ class VashtaNerada(monsters.Monster):
     saving_throws = "Dex +8"
     damage_immunities = "Bludgeoning"
     damage_resistances = "Lightning"
+    damage_vulnerabilities = "Wood-based"
     challenge_rating = 93
     
 
diff --git a/tests/test_monsters.py b/tests/test_monsters.py
index e3fe4fd..13e2b47 100644
--- a/tests/test_monsters.py
+++ b/tests/test_monsters.py
@@ -1,6 +1,6 @@
 from unittest import TestCase
 
-from dungeonsheets import monsters
+from dungeonsheets import monsters, spells
 
 
 class AutoGeneratedMonsters(TestCase):
@@ -351,3 +351,14 @@ class AutoGeneratedMonsters(TestCase):
         self.assertEqual(wolf.strength.value, 12)
         self.assertEqual(wolf.strength.modifier, 1)
         self.assertEqual(wolf.strength.saving_throw, 1)
+
+class MonsterSpellcastingTests(TestCase):
+    def test_spells(self):
+        # Check that monster spells can be set, and then resolved to real spell objects
+        class MyMonster(monsters.Monster):
+            spells = ["cure wounds", spells.Bane]
+
+        self.assertIsInstance(MyMonster.spells[0], type,
+                              msg="Monster spell is not a class")
+        self.assertTrue(issubclass(MyMonster.spells[0], spells.Spell))
+        
diff --git a/tests/test_readers.py b/tests/test_readers.py
index aa91c33..c0d2801 100644
--- a/tests/test_readers.py
+++ b/tests/test_readers.py
@@ -93,7 +93,7 @@ class Roll20ReaderTests(unittest.TestCase):
                 "warhammer",
                 "unarmed strike",
             ],
-            _proficiencies_text=[
+            proficiencies_text=[
                 "Brewer's Supplies",
             ],
             languages="common, dwarvish",
@@ -204,7 +204,7 @@ class FoundryReaderTests(unittest.TestCase):
                 "crossbow",
                 "knives",
             ],
-            _proficiencies_text=[
+            proficiencies_text=[
                 "artisan's tools",
                 "disguise kit",
                 "forger's kit",