diff --git a/app/__init__.py b/app/__init__.py
index 0408b19..1f14007 100644
--- a/app/__init__.py
+++ b/app/__init__.py
@@ -18,7 +18,7 @@ app.config['MONSTERS_JSON_PATH'] = MONSTERS_JSON_PATH
 
 def init():
     from app.routes import coinflip, roll_chance, roll_dice, table_views, encounter, character, \
-        ability_check, mental_attack, physical_attack, get_monster
+        ability_check, mental_attack, physical_attack, get_creature
     # root namespace
     restx_api.add_namespace(coinflip.namespace)
     # dice namespace
@@ -27,7 +27,7 @@ def init():
     # rules namespace
     restx_api.add_namespace(table_views.namespace)
     restx_api.add_namespace(character.namespace)
-    restx_api.add_namespace(get_monster.namespace)
+    restx_api.add_namespace(get_creature.namespace)
     # gameplay namespace
     restx_api.add_namespace(encounter.namespace)
     restx_api.add_namespace(ability_check.namespace)
diff --git a/app/functions/get_attack_roll_outcome.py b/app/functions/get_attack_roll_outcome.py
index 454517d..88c8241 100644
--- a/app/functions/get_attack_roll_outcome.py
+++ b/app/functions/get_attack_roll_outcome.py
@@ -2,6 +2,8 @@ from app.functions.roll_dices import roll_dices
 
 
 def get_attack_roll_outcome(result, modifier=0):
+    if modifier is None:
+        modifier = 0
     outcome = 'Unknown'
     raw_roll = roll_dices(1, 20, False).get('result')
     needed = result['needed']
diff --git a/app/functions/roll_physical_attack.py b/app/functions/roll_physical_attack.py
index 4d6366d..bfc5143 100644
--- a/app/functions/roll_physical_attack.py
+++ b/app/functions/roll_physical_attack.py
@@ -10,8 +10,10 @@ def roll_physical_attack(dac, modifier=0, awc=None, ahd=None):
     :param ahd: integer. optional(*). Attacker hit dice. This is required, if weapon attack == False.
     :return:
     """
-    result = {}
+    if modifier is None:
+        modifier = 0
 
+    result = {}
     if isinstance(awc, int):
         hit_table = AttackerWeaponClassMatrix()
         result["needed"] = hit_table.get_attack_score(awc, dac)
diff --git a/app/models/__init__.py b/app/models/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/app/models/models.py b/app/models/models.py
deleted file mode 100644
index 7ba8562..0000000
--- a/app/models/models.py
+++ /dev/null
@@ -1,133 +0,0 @@
-from flask_restx import fields
-
-# Common fields
-chartype_field = fields.String(
-    required=True,
-    default="human",
-    description='Character type. Allowed values: "human", "humanoid", "mutant", "cyborg"'
-)
-
-conscore_field = fields.Integer(
-        required=True,
-        default=10,
-        min=3,
-        max=18,
-        description='The characters constitution score'
-)
-
-check_model = {
-    'ability_score': fields.Integer(
-        required=True,
-        default=10,
-        min=3,
-        max=21,
-        description='The score of the ability to check against'
-    ),
-    'multiplier': fields.Integer(
-        required=True,
-        default=4,
-        min=2, max=8,
-        description='Sets the threshold for the check. In general, the higher the multiplier, the higher the '
-                    'likelihood of success. Range: 2 - 7'
-    )
-}
-
-# Mutations Model
-mutation_model = {
-    'conscore': conscore_field,
-    'intscore': fields.Integer(
-        required=True,
-        default=10,
-        min=3,
-        max=21,
-        description='The characters intelligence score'
-    )
-}
-# Dice model
-dice_model = {
-    'quantity': fields.Integer(required=True, default=1, description='The number of dice to roll'),
-    'geometry': fields.Integer(required=True, default=2, description='The number of sides on each die'),
-    'discard_lowest': fields.Boolean(required=False, default=False, description='Drop the lowest score')
-}
-
-# Ability model
-ability_model = {
-    'chartype': chartype_field,
-    'ability': fields.String(
-        required=False,
-        default="all",
-        description='The ability to roll. Not required. Valid options: "m-strength", "p-strength", '
-                    '"intelligence", "charisma", "constitution", "dexterity", "all". Defaults to "all".'),
-}
-
-# Hp model
-hp_model = {
-    'chartype': chartype_field,
-    'conscore': conscore_field
-}
-
-
-pa_model = {
-    'weapon_attack': fields.Boolean(
-        required=True,
-        default=True,
-        description='Is the attacker using a weapon? If so, To-Hit is based on weapon class.'
-    ),
-    'dac': fields.Integer(
-        required=True,
-        min=1,
-        max=10,
-        default=1,
-        description='The defenders armour class. This is needed for both weapon attacks and non-weapon attacks'
-    ),
-    'awc': fields.Integer(
-        required=False,
-        min=1,
-        max=16,
-        default=1,
-        description='The attackers weapon class. This is needed for weapon attacks only.'
-    ),
-    'ahd': fields.Integer(
-        required=False,
-        min=1,
-        max=16,
-        default=1,
-        description='The attackers hit dice count. This is needed for non-weapon attacks only.'
-    ),
-    'modifier': fields.Integer(
-        required=False,
-        min=-100,
-        max=100,
-        default=0,
-        description='The roll modifier to be applied to the hit roll.'
-    )
-}
-
-
-ma_model = {
-    'ams': fields.Integer(
-        required=True,
-        min=3,
-        max=18,
-        default=10,
-        description='Attacker Mental Strength'
-    ),
-    'dms': fields.Integer(
-        required=True,
-        min=3,
-        max=18,
-        default=10,
-        description='Defender Mental Strength'
-    ),
-    'modifier': fields.Integer(
-        required=False,
-        min=-100,
-        max=100,
-        default=0,
-        description='Modifier For Mental Attack Roll'),
-}
-
-character_model = {
-    'chartype': chartype_field,
-}
-
diff --git a/app/routes/ability_check.py b/app/routes/ability_check.py
index 710506c..02213d3 100644
--- a/app/routes/ability_check.py
+++ b/app/routes/ability_check.py
@@ -1,20 +1,27 @@
 from flask import request
-from flask_restx import Resource, Namespace
+from flask_restx import Resource, Namespace, reqparse
 
 from app.functions.roll_ability_check import roll_ability_check
 
 namespace = Namespace('gameplay', description='Gamma World Rules')
+# Define the parser and request args:
+parser = reqparse.RequestParser()
+parser.add_argument('score', type=int, required=True,
+                    help='The score of the ability to be checked (3 - 21)')
+parser.add_argument('multiplier', type=int, required=True,
+                    help='The score multiplier for this check attempt (2 - 10)')
 
 
 @namespace.route('/ability/check')  # resolves to: /gameplay/ability/check
 class AbilityCheck(Resource):
-    @namespace.doc(params={'score': 'The ability score', 'multiplier': 'Score multiplier for the attempt.'})
+    @namespace.expect(parser)
     def get(self):
         score = request.args.get('score', type=int)
         multiplier = request.args.get('multiplier', type=float)
-
-        if not score or not multiplier:
-            return {'error': 'Both score and multiplier parameters are required.'}, 400
+        if score < 3 or score > 21:
+            return {'message': 'Ability score must be between 3 and 21'}, 400
+        if multiplier < 2 or multiplier > 10:
+            return {'message': 'Multiplier must be between 2 and 10'}, 400
 
         outcome = roll_ability_check(score, multiplier)
         return outcome, 200
diff --git a/app/routes/character.py b/app/routes/character.py
index 0981887..6866ec5 100644
--- a/app/routes/character.py
+++ b/app/routes/character.py
@@ -1,25 +1,28 @@
 from flask import request
-from flask_restx import Resource, Namespace
+from flask_restx import Resource, Namespace, reqparse
 
 from app.functions.build_character_sheet import build_character_sheet
 
 namespace = Namespace('rules', description='Gamma World Rules')
 
-VALID_CHARTYPES = ["human", "humanoid", "mutant", "cyborg"]
+parser = reqparse.RequestParser()
+parser.add_argument('chartype', type=str, default='Human',
+                    help='The Character Type for the new character (human, humanoid, mutant, cyborg)')
 
 
 @namespace.route('/character')  # resolves to: /rules/character
 class GenerateCharacter(Resource):
-    @namespace.doc(params={'chartype': 'The Character Type for the new character'})
+    @namespace.expect(parser)
     def get(self):
+        valid_chartypes = ["human", "humanoid", "mutant", "cyborg"]
         chartype = request.args.get('chartype', default='Human', type=str)
         if chartype:
-            if chartype.lower() in VALID_CHARTYPES:
+            if chartype.lower() in valid_chartypes:
                 return build_character_sheet(chartype.lower()), 200
             else:
                 return {
                     'error': 'Invalid character type provided.',
-                    'valid_chartypes': VALID_CHARTYPES
+                    'valid_chartypes': valid_chartypes
                 }, 400
         else:
-            return {'error': 'No character type provided', 'valid_chartypes': VALID_CHARTYPES}, 400
+            return {'error': 'No character type provided', 'valid_chartypes': valid_chartypes}, 400
diff --git a/app/routes/encounter.py b/app/routes/encounter.py
index 56204d6..655b632 100644
--- a/app/routes/encounter.py
+++ b/app/routes/encounter.py
@@ -1,26 +1,28 @@
 from flask import request
-from flask_restx import Resource, Namespace
-
+from flask_restx import Resource, Namespace, reqparse
 from app.functions.roll_encounter import roll_encounter
 
 namespace = Namespace('gameplay', description='Gamma World Game Play')
 
-VALID_TERRAINS = ["clear", "mountains", "forest", "desert", "watery", "ruins", "deathlands"]
+parser = reqparse.RequestParser()
+parser.add_argument('terrain', type=str, default='clear',
+                    help='The terrain being traversed. ("clear", "mountains", "forest", "desert",'
+                         '"watery", "ruins", "deathlands")')
 
 
 @namespace.route('/encounter')  # resolves to: /gameplay/encounter
 class RollEncounter(Resource):
-    @namespace.doc(params={'terrain': 'The terrain type for the encounter'})
+    @namespace.expect(parser)
     def get(self):
-        terrain = request.args.get('terrain', default=None, type=str)
-
+        terrain = request.args.get('terrain', default="clear", type=str)
+        valid_terrains = ["clear", "mountains", "forest", "desert", "watery", "ruins", "deathlands"]
         if terrain:
-            if terrain.lower() in VALID_TERRAINS:
+            if terrain.lower() in valid_terrains:
                 return roll_encounter(terrain.lower()), 200
             else:
                 return {
                     'error': 'Invalid terrain type provided.',
-                    'valid_terrains': VALID_TERRAINS
+                    'valid_terrains': valid_terrains
                 }, 400
         else:
-            return {'error': 'No terrain type provided', 'valid_terrains': VALID_TERRAINS}, 400
+            return {'error': 'No terrain type provided', 'valid_terrains': valid_terrains}, 400
diff --git a/app/routes/get_creature.py b/app/routes/get_creature.py
new file mode 100644
index 0000000..eb31429
--- /dev/null
+++ b/app/routes/get_creature.py
@@ -0,0 +1,18 @@
+from flask import request
+from flask_restx import Resource, Namespace, reqparse
+from app.tables.creature import Creatures
+
+namespace = Namespace('rules', description='Gamma World Rules')
+parser = reqparse.RequestParser()
+parser.add_argument('creature', type=str, help='the name of a Gamma World creature to search for.')
+
+
+@namespace.route('/creature')  # resolves to: /rules/creature
+class RollEncounter(Resource):
+    @namespace.expect(parser)
+    def get(self):
+        creature = request.args.get('creature', default=None, type=str)
+        if creature is None:
+            return {'error': 'Provide the name of a Gamma World creature to search for'}, 400
+        creatures = Creatures()
+        return creatures.get_creature(creature), 200
diff --git a/app/routes/get_monster.py b/app/routes/get_monster.py
deleted file mode 100644
index ae55e67..0000000
--- a/app/routes/get_monster.py
+++ /dev/null
@@ -1,19 +0,0 @@
-from flask import request
-from flask_restx import Resource, Namespace
-
-from app.tables.monsters import Monsters
-
-namespace = Namespace('rules', description='Gamma World Rules')
-
-
-@namespace.route('/creature')  # resolves to: /gameplay/encounter
-class RollEncounter(Resource):
-    @namespace.doc(params={'creature': 'The terrain type for the encounter'})
-    def get(self):
-        creature = request.args.get('creature', default=None, type=str)
-
-        if creature is None:
-            return {'error': 'Provide the name of a Gamma World creature to search for'}, 400
-
-        monsters = Monsters()
-        return monsters.get_monster(creature), 200
diff --git a/app/routes/mental_attack.py b/app/routes/mental_attack.py
index 7fe089f..74d9f7a 100644
--- a/app/routes/mental_attack.py
+++ b/app/routes/mental_attack.py
@@ -1,19 +1,30 @@
 from flask import request
-from flask_restx import Resource, Namespace
+from flask_restx import Resource, Namespace, reqparse
 
 from app.functions.roll_mental_attack import roll_mental_attack
 
 namespace = Namespace('gameplay', description='Gamma World Rules')
 
+# doc(params={'ams': 'Attacker Mental Strength',
+#                            'dms': 'Defender Mental Strength',
+#                            'modifier': 'Roll Modifier'})
+
+parser = reqparse.RequestParser()
+parser.add_argument('ams', type=int, required=True, help='Attacker Mental Strength (1 - 18)')
+parser.add_argument('dms', type=int, required=True, help='Defender Mental Strength (1 - 18)')
+parser.add_argument('modifier', type=int, required=True, help='Roll Modifier')
+
 
 @namespace.route('/attack/mental')  # resolves to: /gameplay/attack/mental
 class MentalAttack(Resource):
-    @namespace.doc(params={'ams': 'Attacker Mental Strength',
-                           'dms': 'Defender Mental Strength',
-                           'modifier': 'Roll Modifier'})
+    @namespace.expect(parser)
     def get(self):
         ams = request.args.get('ams', type=int)
         dms = request.args.get('dms', type=int)
         modifier = request.args.get('modifier', type=int)
-        # Validate params here
+        if ams < 1 or ams > 18:
+            return {'message': 'Attacker Mental Strength must be between 1 and 18'}, 400
+        if dms < 1 or dms > 18:
+            return {'message': 'Defender Mental Strength must be between 1 and 18'}, 400
+
         return roll_mental_attack(ams, dms, modifier), 200
diff --git a/app/routes/physical_attack.py b/app/routes/physical_attack.py
index 0429204..dd7833a 100644
--- a/app/routes/physical_attack.py
+++ b/app/routes/physical_attack.py
@@ -1,18 +1,20 @@
 from flask import request
-from flask_restx import Resource, Namespace
+from flask_restx import Resource, Namespace, reqparse
 
 from app.functions.roll_physical_attack import roll_physical_attack
 
 namespace = Namespace('gameplay', description='Gamma World Rules')
 
+parser = reqparse.RequestParser()
+parser.add_argument('dac', type=int, required=True, help='REQUIRED: Defender Armour Class. Needed for both attacks')
+parser.add_argument('awc', type=int, help='OPTIONAL(*): Attacker Weapon Class. Only needed for weapon attacks')
+parser.add_argument('ahd', type=int, help='OPTIONAL(*): Attacker Hit Dice. Only needed for non-weapon attacks')
+parser.add_argument('modifier', type=int, help='OPTIONAL: Roll Modifier')
+
 
 @namespace.route('/attack/physical')  # resolves to: /gameplay/attack/physical
 class PhysicalAttack(Resource):
-    @namespace.doc(
-        params={'dac': 'REQUIRED: Needed for both attacks',
-                'modifier': 'OPTIONAL: Roll Modifier',
-                'awc': 'OPTIONAL(*): Attacker Weapon Class. Only needed for weapon attacks',
-                'ahd': 'OPTIONAL(*): Attacker Hit Dice. Only needed for non-weapon attacks'})
+    @namespace.expect(parser)
     def get(self):
         dac = request.args.get('dac', type=int)
         awc = request.args.get('awc', type=int)
diff --git a/app/routes/roll_dice.py b/app/routes/roll_dice.py
index e8ae163..7cfb653 100644
--- a/app/routes/roll_dice.py
+++ b/app/routes/roll_dice.py
@@ -1,24 +1,25 @@
-from flask_restx import Resource, Namespace
+from flask_restx import Resource, Namespace, reqparse
 from app.functions.roll_dices import roll_dices
-from app.models.models import dice_model
-from app.schemas.schemas import DiceSchema
 
 namespace = Namespace('dice', description='Dice Operations')
-dice_model = namespace.model('Dice', dice_model)
-dice_schema = DiceSchema()
+
+# Define the parser and request args:
+parser = reqparse.RequestParser()
+parser.add_argument('quantity', type=int, required=True, help='Quantity of dice to roll')
+parser.add_argument('geometry', type=int, required=True, help='Number of faces on the dice')
+parser.add_argument('discard_lowest', type=bool, required=True, help='Whether to discard lowest roll')
 
 
 @namespace.route('/')  # resolves to: /dice
 class RollDice(Resource):
-    @namespace.expect(dice_model)
-    def post(self):
-        data = namespace.payload
-        errors = dice_schema.validate(data)
-        if errors:
-            return errors, 400
-        quantity = data.get('quantity')
-        geometry = data.get('geometry')
-        discard_lowest = data.get('discard_lowest')
-        if quantity is None or geometry is None:
-            return {"message": "Required dice data not provided"}, 400
+    @namespace.expect(parser)
+    def get(self):
+        args = parser.parse_args()
+        quantity = args['quantity']
+        geometry = args['geometry']
+        discard_lowest = args['discard_lowest']
+        if quantity < 1 or quantity > 100:
+            return {'message': 'Quantity must be between 1 and 100'}, 400
+        if geometry < 3 or geometry > 100:
+            return {'message': 'Geometry must be between 3 and 100'}, 400
         return roll_dices(quantity, geometry, discard_lowest), 200
diff --git a/app/schemas/__init__.py b/app/schemas/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/app/schemas/schemas.py b/app/schemas/schemas.py
deleted file mode 100644
index 163aa9c..0000000
--- a/app/schemas/schemas.py
+++ /dev/null
@@ -1,130 +0,0 @@
-from marshmallow import Schema, fields, validate
-
-chartype_field = fields.String(
-    required=True,
-    validate=validate.OneOf(["human", "humanoid", "mutant", "cyborg"]),
-    description='The characters type of being'
-)
-
-conscore_field = fields.Integer(
-    required=True,
-    default=10,
-    validate=validate.Range(min=3, max=18),
-    description='The constitution score of the character'
-)
-
-
-class MutationSchema(Schema):
-    conscore = conscore_field
-    intscore = fields.Integer(
-        required=True,
-        validate=validate.Range(min=3, max=18),
-        description='The characters intelligence score'
-    )
-
-
-class HPSchema(Schema):
-    chartype = chartype_field
-    conscore = conscore_field
-
-
-class DiceSchema(Schema):
-    quantity = fields.Int(
-        required=True,
-        default=1,
-        validate=validate.Range(min=1),
-        description='The number of dice to roll'
-    )
-    geometry = fields.Int(
-        required=True,
-        default=2,
-        validate=validate.Range(min=2),
-        description='The number of sides on each die'
-    )
-    discard_lowest = fields.Bool(required=True, default=False, description='Drop the lowest score')
-
-
-class CharacterSchema(Schema):
-    chartype = chartype_field
-
-
-class AbilitySchema(Schema):
-    chartype = chartype_field
-    ability = fields.String(
-        required=False,
-        default="generic",
-        validate=validate.OneOf(
-            ["m-strength", "p-strength", "intelligence", "charisma", "constitution", "dexterity", "all"]),
-        description='One of the six character attributes from the character sheet'
-    )
-
-
-class CheckSchema(Schema):
-    ability_score = fields.Integer(
-        required=True,
-        default=10,
-        validate=validate.Range(min=3, max=21),
-        description='The score of the ability to be checked against'
-    )
-    multiplier = fields.Integer(
-        required=True,
-        default=4,
-        validate=validate.Range(min=2, max=8),
-        description='Sets the threshold for the check. In general, the higher the multiplier, the higher the '
-                    'likelihood of success. Range: 2 - 7'
-    )
-
-
-class MentalAttackSchema(Schema):
-    ams = fields.Integer(
-        required=True,
-        validate=validate.Range(min=3, max=18),
-        description='The Attackers Mental Strength'
-    )
-    dms = fields.Integer(
-        required=True,
-        validate=validate.Range(min=3, max=18),
-        description='The Defenders Mental Strength'
-    )
-    modifier = fields.Integer(
-        required=False,
-        default=0,
-        validate=validate.Range(min=-100, max=100),
-        description='Roll modifier for mental attack'
-    )
-
-
-class PhysicalAttackSchema(Schema):
-    weapon_attack = fields.Boolean(
-        required=True,
-        default=True,
-        description="Is the attacker using a weapon? If so, To-Hit is based on weapon class."
-    )
-    dac = fields.Integer(
-        required=True,
-        min=1,
-        max=10,
-        default=1,
-        description='The defenders armour class. This is needed for both weapon attacks and non-weapon attacks'
-    )
-    awc = fields.Integer(
-        required=False,
-        min=1,
-        max=16,
-        default=1,
-        description='The attackers weapon class. This is needed for weapon attacks only.'
-    )
-    ahd = fields.Integer(
-        required=False,
-        min=1,
-        max=16,
-        default=1,
-        description='The attackers hit dice count. This is needed for non-weapon attacks only.'
-    )
-    modifier = fields.Integer(
-        required=False,
-        min=-100,
-        max=100,
-        default=0,
-        description='The roll modifier to be applied to the hit roll.'
-    )
diff --git a/app/tables/creature.py b/app/tables/creature.py
new file mode 100644
index 0000000..318708b
--- /dev/null
+++ b/app/tables/creature.py
@@ -0,0 +1,19 @@
+import json
+
+
+class Creatures:
+    creatures = None
+
+    @staticmethod
+    def load_creature_data():
+        """Loads the monsters data from a JSON file"""
+        with open('app/tables/creatures.json') as f:
+            Creatures.creatures = json.load(f)
+
+    def __init__(self):
+        if not Creatures.creatures:
+            self.load_creature_data()
+
+    def get_creature(self, creature_name):
+        """Returns the dictionary of the specified creature."""
+        return self.creatures.get(creature_name)
diff --git a/app/tables/monsters.json b/app/tables/creatures.json
similarity index 100%
rename from app/tables/monsters.json
rename to app/tables/creatures.json
diff --git a/app/tables/monsters.py b/app/tables/monsters.py
deleted file mode 100644
index 7e12163..0000000
--- a/app/tables/monsters.py
+++ /dev/null
@@ -1,28 +0,0 @@
-import json
-
-
-class Monsters:
-    monsters = None
-
-    @staticmethod
-    def load_monsters_data():
-        """Loads the monsters data from a JSON file"""
-        with open('app/tables/monsters.json') as f:
-            Monsters.monsters = json.load(f)
-
-    def __init__(self):
-        if not Monsters.monsters:
-            self.load_monsters_data()
-
-    def get_monster(self, monster_name):
-        """Returns the dictionary of the specified monster."""
-        return self.monsters.get(monster_name)
-
-    def add_monster(self, monster_name, attributes):
-        """Adds a new monster to the monsters dictionary."""
-        self.monsters[monster_name] = attributes
-
-    def remove_monster(self, monster_name):
-        """Removes a monster from the monsters dictionary."""
-        if monster_name in self.monsters:
-            del self.monsters[monster_name]
diff --git a/config.py b/config.py
index fb5bb62..1de0899 100644
--- a/config.py
+++ b/config.py
@@ -3,4 +3,4 @@ import os
 
 BASE_DIR = os.path.dirname(os.path.abspath(__file__))
 DATA_DIR = os.path.join(BASE_DIR, 'app/tables')
-MONSTERS_JSON_PATH = os.path.join(DATA_DIR, 'monsters.json')
+MONSTERS_JSON_PATH = os.path.join(DATA_DIR, 'creatures.json')