diff --git a/system/str.php b/system/str.php
index 7ab40159..ec446c34 100644
--- a/system/str.php
+++ b/system/str.php
@@ -46,6 +46,17 @@ public static function title($value)
         return (function_exists('mb_convert_case')) ? mb_convert_case($value, MB_CASE_TITLE, Config::get('application.encoding')) : ucwords(strtolower($value));
     }
 
+    /**
+     * Get the length of a string.
+     *
+     * @param  string  $value
+     * @return int
+     */
+    public static function length($value)
+    {
+        return function_exists('mb_strlen') ? mb_strlen($value, Config::get('application.encoding')) : strlen($value);
+    }
+
     /**
      * Generate a random alpha or alpha-numeric string.
      *
diff --git a/system/validation/error_collector.php b/system/validation/error_collector.php
new file mode 100644
index 00000000..13285ce8
--- /dev/null
+++ b/system/validation/error_collector.php
@@ -0,0 +1,70 @@
+<?php namespace System\Validation;
+
+class Error_Collector {
+
+	/**
+	 * All of the error messages.
+	 *
+	 * @var array
+	 */
+	public $messages;
+
+	/**
+	 * Create a new Error Collector instance.
+	 *
+	 * @return void
+	 */
+	public function __construct($messages = array())
+	{
+		$this->messages = $messages;
+	}
+
+	/**
+	 * Add an error message to the collector.
+	 *
+	 * @param  string  $attribute
+	 * @param  string  $message
+	 * @return void
+	 */
+	public function add($attribute, $message)
+	{
+		$this->messages[$attribute][] = $message;
+	}
+
+	/**
+	 * Get the first error message for an attribute.
+	 *
+	 * @param  string  $attribute
+	 * @return string
+	 */
+	public function first($attribute)
+	{
+		return (count($messages = $this->get($attribute)) > 0) ? $messages[0] : '';
+	}
+
+	/**
+	 * Get all of the error messages for an attribute.
+	 *
+	 * If no attribute is specified, all of the error messages will be returned.
+	 *
+	 * @param  string  $attribute
+	 * @return array
+	 */
+	public function get($attribute = null)
+	{
+		if (is_null($attribute))
+		{
+			$all = array();
+
+			foreach ($this->messages as $messages)
+			{
+				$all = array_merge($all, $messages);
+			}
+
+			return $all;
+		}
+
+		return (array_key_exists($attribute, $this->messages)) ? $this->messages[$attribute] : array();
+	}
+
+}
\ No newline at end of file
diff --git a/system/validation/rule.php b/system/validation/rule.php
new file mode 100644
index 00000000..d3e79289
--- /dev/null
+++ b/system/validation/rule.php
@@ -0,0 +1,93 @@
+<?php namespace System\Validation;
+
+abstract class Rule {
+
+	/**
+	 * The attributes being validated.
+	 *
+	 * @var array
+	 */
+	public $attributes;
+
+	/**
+	 * The validation error message.
+	 *
+	 * @var string
+	 */
+	public $message;
+
+	/**
+	 * Create a new validation Rule instance.
+	 *
+	 * @param  array      $attributes
+	 * @param  Validator  $class
+	 * @return void
+	 */
+	public function __construct($attributes)
+	{
+		$this->attributes = $attributes;
+	}
+
+	/**
+	 * Run the validation rule.
+	 *
+	 * @param  array            $attributes
+	 * @param  Error_Collector  $errors
+	 * @return void
+	 */
+	public function validate($attributes, $errors)
+	{
+		if (is_null($this->message))
+		{
+			throw new \Exception("An error message must be specified for every Eloquent validation rule.");
+		}
+
+		foreach ($this->attributes as $attribute)
+		{
+			if ( ! $this->check($attribute, $attributes))
+			{
+				$errors->add($attribute, $this->prepare_message($attribute));
+			}
+		}
+	}
+
+	/**
+	 * Prepare the message to be added to the error collector.
+	 *
+	 * Attribute and size place-holders will replace with their actual values.
+	 *
+	 * @param  string  $attribute
+	 * @return string
+	 */
+	private function prepare_message($attribute)
+	{
+		$message = $this->message;
+
+		if (strpos($message, ':attribute'))
+		{
+			$message = str_replace(':attribute', Lang::line('attributes.'.$attribute)->get(), $message);
+		}
+
+		if ($this instanceof Rules\Size_Of)
+		{
+			$message = str_replace(':max', $this->maximum, $message);
+			$message = str_replace(':min', $this->minimum, $message);
+			$message = str_replace(':size', $this->length, $message);
+		}
+
+		return $message;
+	}
+
+	/**
+	 * Set the validation error message.
+	 *
+	 * @param  string  $message
+	 * @return Rule
+	 */
+	public function message($message)
+	{
+		$this->message = $message;
+		return $this;
+	}
+
+}
\ No newline at end of file
diff --git a/system/validation/rules/acceptance_of.php b/system/validation/rules/acceptance_of.php
new file mode 100644
index 00000000..001c9a30
--- /dev/null
+++ b/system/validation/rules/acceptance_of.php
@@ -0,0 +1,39 @@
+<?php namespace System\Validation\Rules;
+
+use System\Input;
+use System\Validation\Rule;
+
+class Acceptance_Of extends Rule {
+
+	/**
+	 * The value is that is considered accepted.
+	 *
+	 * @var string
+	 */
+	public $accepts = '1';
+
+	/**
+	 * Evaluate the validity of an attribute.
+	 *
+	 * @param  string  $attribute
+	 * @param  array   $attributes
+	 * @return void
+	 */
+	public function check($attribute, $attributes)
+	{
+		return Input::has($attribute) and (string) Input::get($attribute) === $this->accepts;
+	}	
+
+	/**
+	 * Set the accepted value.
+	 *
+	 * @param  string  $value
+	 * @return Acceptance_Of
+	 */
+	public function accepts($value)
+	{
+		$this->accepts = $value;
+		return $this;
+	}
+
+}
\ No newline at end of file
diff --git a/system/validation/rules/confirmation_of.php b/system/validation/rules/confirmation_of.php
new file mode 100644
index 00000000..02185cca
--- /dev/null
+++ b/system/validation/rules/confirmation_of.php
@@ -0,0 +1,25 @@
+<?php namespace System\Validation\Rules;
+
+use System\Input;
+use System\Validation\Rule;
+
+class Confirmation_Of extends Rule {
+
+	/**
+	 * Evaluate the validity of an attribute.
+	 *
+	 * @param  string  $attribute
+	 * @param  array   $attributes
+	 * @return void
+	 */
+	public function check($attribute, $attributes)
+	{
+		if ( ! array_key_exists($attribute, $attributes))
+		{
+			return true;
+		}
+
+		return Input::has($attribute.'_confirmation') and $attributes[$attribute] === Input::get($attribute.'_confirmation');
+	}
+
+}
\ No newline at end of file
diff --git a/system/validation/rules/exclusion_of.php b/system/validation/rules/exclusion_of.php
new file mode 100644
index 00000000..df0f6318
--- /dev/null
+++ b/system/validation/rules/exclusion_of.php
@@ -0,0 +1,43 @@
+<?php namespace System\Validation\Rules;
+
+use System\Validation\Rule;
+
+class Exclusion_Of extends Rule {
+
+	/**
+	 * The reserved values for the attribute.
+	 *
+	 * @var string
+	 */
+	public $reserved;
+
+	/**
+	 * Evaluate the validity of an attribute.
+	 *
+	 * @param  string  $attribute
+	 * @param  array   $attributes
+	 * @return void
+	 */
+	public function check($attribute, $attributes)
+	{
+		if ( ! array_key_exists($attribute, $attributes))
+		{
+			return true;
+		}
+
+		return ! in_array($attributes[$attribute], $this->reserved);
+	}	
+
+	/**
+	 * Set the reserved values for the attribute
+	 *
+	 * @param  array  $reserved
+	 * @return Exclusion_Of
+	 */
+	public function from($reserved)
+	{
+		$this->reserved = $reserved;
+		return $this;
+	}
+
+}
\ No newline at end of file
diff --git a/system/validation/rules/format_of.php b/system/validation/rules/format_of.php
new file mode 100644
index 00000000..df0cd2de
--- /dev/null
+++ b/system/validation/rules/format_of.php
@@ -0,0 +1,43 @@
+<?php namespace System\Validation\Rules;
+
+use System\Validation\Rule;
+
+class Format_Of extends Rule {
+
+	/**
+	 * The regular expression that will be used to evaluate the attribute.
+	 *
+	 * @var string
+	 */
+	public $expression;
+
+	/**
+	 * Evaluate the validity of an attribute.
+	 *
+	 * @param  string  $attribute
+	 * @param  array   $attributes
+	 * @return void
+	 */
+	public function check($attribute, $attributes)
+	{
+		if ( ! array_key_exists($attribute, $attributes))
+		{
+			return true;
+		}
+
+		return preg_match($this->expression, $attributes[$attribute]);
+	}	
+
+	/**
+	 * Set the regular expression.
+	 *
+	 * @param  string  $expression
+	 * @return Format_Of
+	 */
+	public function with($expression)
+	{
+		$this->expression = $expression;
+		return $this;
+	}
+
+}
\ No newline at end of file
diff --git a/system/validation/rules/inclusion_of.php b/system/validation/rules/inclusion_of.php
new file mode 100644
index 00000000..db1e0afb
--- /dev/null
+++ b/system/validation/rules/inclusion_of.php
@@ -0,0 +1,43 @@
+<?php namespace System\Validation\Rules;
+
+use System\Validation\Rule;
+
+class Inclusion_Of extends Rule {
+
+	/**
+	 * The accepted values for the attribute.
+	 *
+	 * @var string
+	 */
+	public $accepted;
+
+	/**
+	 * Evaluate the validity of an attribute.
+	 *
+	 * @param  string  $attribute
+	 * @param  array   $attributes
+	 * @return void
+	 */
+	public function check($attribute, $attributes)
+	{
+		if ( ! array_key_exists($attribute, $attributes))
+		{
+			return true;
+		}
+
+		return in_array($attributes[$attribute], $this->accepted);
+	}	
+
+	/**
+	 * Set the accepted values for the attribute.
+	 *
+	 * @param  array  $accepted
+	 * @return Inclusion_Of
+	 */
+	public function in($accepted)
+	{
+		$this->accepted = $accepted;
+		return $this;
+	}
+
+}
\ No newline at end of file
diff --git a/system/validation/rules/presence_of.php b/system/validation/rules/presence_of.php
new file mode 100644
index 00000000..06c05fd5
--- /dev/null
+++ b/system/validation/rules/presence_of.php
@@ -0,0 +1,70 @@
+<?php namespace System\Validation\Rules;
+
+use System\Validation\Rule;
+
+class Presence_Of extends Rule {
+
+	/**
+	 * Indicates an empty string should be considered present.
+	 *
+	 * @var bool
+	 */
+	public $allow_empty = false;
+
+	/**
+	 * Indicates a null should be considered present.
+	 *
+	 * @var bool
+	 */
+	public $allow_null = false;
+
+	/**
+	 * Evaluate the validity of an attribute.
+	 *
+	 * @param  string  $attribute
+	 * @param  array   $attributes
+	 * @return void
+	 */
+	public function check($attribute, $attributes)
+	{
+		if ( ! array_key_exists($attribute, $attributes))
+		{
+			return false;
+		}
+
+		if (is_null($attributes[$attribute]) and ! $this->allow_null)
+		{
+			return false;
+		}
+
+		if (trim((string) $attributes[$attribute]) === '' and ! $this->allow_empty)
+		{
+			return false;
+		}
+
+		return true;
+	}
+
+	/**
+	 * Allow an empty string to be considered present.
+	 *
+	 * @return Presence_Of
+	 */
+	public function allow_empty()
+	{
+		$this->allow_empty = true;
+		return $this;
+	}
+
+	/**
+	 * Allow a null to be considered present.
+	 *
+	 * @return Presence_Of
+	 */
+	public function allow_null()
+	{
+		$this->allow_null = true;
+		return $this;
+	}
+
+}
\ No newline at end of file
diff --git a/system/validation/rules/size_of.php b/system/validation/rules/size_of.php
new file mode 100644
index 00000000..8cefa1f6
--- /dev/null
+++ b/system/validation/rules/size_of.php
@@ -0,0 +1,160 @@
+<?php namespace System\Validation\Rules;
+
+use System\Str;
+use System\Validation\Rule;
+
+class Size_Of extends Rule {
+
+	/**
+	 * The exact size the attribute must be.
+	 *
+	 * @var int
+	 */
+	public $length;
+
+	/**
+	 * The maximum size of the attribute.
+	 *
+	 * @var int
+	 */
+	public $maximum;
+
+	/**
+	 * The minimum size of the attribute.
+	 *
+	 * @var int
+	 */
+	public $minimum;
+
+	/**
+	 * Evaluate the validity of an attribute.
+	 *
+	 * @param  string  $attribute
+	 * @param  array   $attributes
+	 * @return void
+	 */
+	public function check($attribute, $attributes)
+	{
+		if ( ! array_key_exists($attribute, $attributes))
+		{
+			return true;
+		}
+
+		if (is_numeric($attributes[$attribute]))
+		{
+			return $this->check_number($attribute, $attributes);
+		}
+		else
+		{
+			return $this->check_string($attribute, $attributes);
+		}
+	}
+
+	/**
+	 * Evaluate the validity of a numeric attribute.
+	 *
+	 * @param  string  $attribute
+	 * @param  array   $attributes
+	 * @return void
+	 */
+	private function check_number($attribute, $attributes)
+	{
+		if ( ! is_null($this->length) and $attributes[$attribute] !== $this->length)
+		{
+			return false;
+		}
+
+		if ( ! is_null($this->maximum) and $attributes[$attribute] > $this->maximum)
+		{
+			return false;
+		}
+
+		if ( ! is_null($this->minimum and $attributes[$attribute] < $this->minimum))
+		{
+			return false;
+		}
+
+		return true;
+	}
+
+	/**
+	 * Evaluate the validity of a string attribute.
+	 *
+	 * @param  string  $attribute
+	 * @param  array   $attributes
+	 * @return void
+	 */
+	public function check_string($attribute, $attributes)
+	{
+		$value = trim((string) $attributes[$attribute]);
+
+		if ( ! is_null($this->length) and Str::length($value) !== $this->length)
+		{
+			return false;
+		}
+
+		if ( ! is_null($this->maximum) and Str::length($value) > $this->maximum)
+		{
+			return false;
+		}
+
+		if ( ! is_null($this->minimum) and Str::length($value) < $this->minimum)
+		{
+			return false;
+		}
+
+		return true;
+	}
+
+	/**
+	 * Set the exact size the attribute must be.
+	 *
+	 * @param  int  $length
+	 * @return Size_Of
+	 */
+	public function is($length)
+	{
+		$this->length = $length;
+		return $this;
+	}
+
+	/**
+	 * Set the minimum and maximize size of the attribute.
+	 *
+	 * @param  int  $minimum
+	 * @param  int  $maximum
+	 * @return Size_Of
+	 */
+	public function between($minimum, $maximum)
+	{
+		$this->minimum = $minimum;
+		$this->maximum = $maximum;
+
+		return $this;
+	}
+
+	/**
+	 * Set the minimum size the attribute.
+	 *
+	 * @param  int  $minimum
+	 * @return Size_Of
+	 */
+	public function at_least($minimum)
+	{
+		$this->minimum = $minimum;
+		return $this;
+	}
+
+	/**
+	 * Set the maximum size the attribute.
+	 *
+	 * @param  int  $maximum
+	 * @return Size_Of
+	 */
+	public function less_than($maximum)
+	{
+		$this->maximum = $maximum;
+		return $this;
+	}
+
+}
\ No newline at end of file
diff --git a/system/validation/rules/uniqueness_of.php b/system/validation/rules/uniqueness_of.php
new file mode 100644
index 00000000..938e813a
--- /dev/null
+++ b/system/validation/rules/uniqueness_of.php
@@ -0,0 +1,60 @@
+<?php namespace System\Validation\Rules;
+
+use System\DB;
+use System\DB\Eloquent;
+use System\Validation\Rule;
+
+class Uniqueness_Of extends Rule {
+
+	/**
+	 * The database table that should be checked.
+	 *
+	 * @var string
+	 */
+	public $table;
+
+	/**
+	 * The database column that should be checked.
+	 *
+	 * @var string
+	 */
+	public $column;
+
+	/**
+	 * Evaluate the validity of an attribute.
+	 *
+	 * @param  string  $attribute
+	 * @param  array   $attributes
+	 * @return void
+	 */
+	public function check($attribute, $attributes)
+	{
+		if ( ! array_key_exists($attribute, $attributes))
+		{
+			return true;
+		}
+
+		if (is_null($this->column))
+		{
+			$this->column = $attribute;
+		}
+
+		return DB::table(Eloquent::table($this->table)->where($this->column, '=', $attributes[$attribute])->count() == 0;
+	}
+
+	/**
+	 * Set the database table and column.
+	 *
+	 * @param  string  $table
+	 * @param  string  $column
+	 * @return Uniqueness_Of
+	 */
+	public function on($table, $column = null)
+	{
+		$this->table = $table;
+		$this->column = $column;
+
+		return $this;
+	}
+
+}
\ No newline at end of file
diff --git a/system/validation/rules/with_callback.php b/system/validation/rules/with_callback.php
new file mode 100644
index 00000000..7ddbb75e
--- /dev/null
+++ b/system/validation/rules/with_callback.php
@@ -0,0 +1,48 @@
+<?php namespace System\Validation\Rules;
+
+use System\Validation\Rule;
+
+class With_Callback extends Rule {
+
+	/**
+	 * The callback.
+	 *
+	 * @var function
+	 */
+	public $callback;
+
+	/**
+	 * Evaluate the validity of an attribute.
+	 *
+	 * @param  string  $attribute
+	 * @param  array   $attributes
+	 * @return void
+	 */
+	public function check($attribute, $attributes)
+	{
+		if ( ! array_key_exists($attribute, $attributes))
+		{
+			return true;
+		}
+
+		if ( ! is_callable($this->callback))
+		{
+			throw new \Exception("A validation callback for the [$attribute] attribute is not callable.");
+		}
+
+		return call_user_func($this->callback, $attributes[$attribute]);
+	}
+
+	/**
+	 * Set the validation callback.
+	 *
+	 * @param  function  $callback
+	 * @return With_Callback
+	 */
+	public function using($callback)
+	{
+		$this->callback = $callback;
+		return $this;
+	}
+
+}
\ No newline at end of file
diff --git a/system/validator.php b/system/validator.php
new file mode 100644
index 00000000..3264dae8
--- /dev/null
+++ b/system/validator.php
@@ -0,0 +1,94 @@
+<?php namespace System;
+
+class Validator {
+
+	/**
+	 * The attributes being validated.
+	 *
+	 * @var array
+	 */
+	public $attributes;
+
+	/**
+	 * The validation error collector.
+	 *
+	 * @var Error_Collector
+	 */
+	public $errors;
+
+	/**
+	 * The validation rules.
+	 *
+	 * @var array
+	 */
+	public $rules = array();
+
+	/**
+	 * Create a new Eloquent validator instance.
+	 *
+	 * @param  mixed  $target
+	 * @return void
+	 */
+	public function __construct($target)
+	{
+		// ---------------------------------------------------------
+		// If the source is an Eloquent model, use the model's
+		// attributes as the validation attributes.
+		// ---------------------------------------------------------
+		$this->attributes = ($target instanceof DB\Eloquent) ? $target->attributes : (array) $target;
+
+		$this->errors = new Validation\Error_Collector;
+	}
+
+	/**
+	 * Create a new Eloquent validator instance.
+	 *
+	 * @param  mixed      $target
+	 * @return Validator
+	 */
+	public static function of($target)
+	{
+		return new static($target);
+	}
+
+	/**
+	 * Determine if the model passes all of the validation rules.
+	 *
+	 * @return bool
+	 */
+	public function is_valid()
+	{
+		$this->errors->messages = array();
+
+		foreach ($this->rules as $rule)
+		{
+			// ---------------------------------------------------------
+			// The error collector is passed to the rule so that the
+			// rule may conveniently add error messages.
+			// ---------------------------------------------------------
+			$rule->validate($this->attributes, $this->errors);
+		}
+
+		return count($this->errors->messages) === 0;
+	}
+
+	/**
+	 * Magic Method for dynamically creating validation rules.
+	 */
+	public function __call($method, $parameters)
+	{
+		// ---------------------------------------------------------
+		// Check if the validation rule is defined in the rules
+		// directory. If it is, create a new rule and return it.
+		// ---------------------------------------------------------
+		if (file_exists(SYS_PATH.'validation/rules/'.$method.EXT))
+		{
+			$rule = '\\System\\Validation\\Rules\\'.$method;
+
+			return $this->rules[] = new $rule($parameters);
+		}
+
+		throw new \Exception("Method [$method] does not exist on Validator class.");
+	}
+
+}
\ No newline at end of file