Notes
Weapon and Armor Proficiency: Beguilers are proficient with all simple weapons plus the hand crossbow, rapier, shortbow, and short sword. Beguilers are proficient with light armor, but not with shields.
Spells: A beguiler casts arcane spells, which are drawn from the beguiler spell list. When you gain access to a new level of spells, you automatically know all the spells for that level on the beguiler's spell list. You can cast any spell you know without preparing it ahead of time. Essentially, your spell list is the same as your spells known list. You also have the option of adding to your existing spell list through your advanced learning class feature (see below) as you increase in level.
To cast a beguiler spell, you must have an Intelligence score of 10 + the spell's level (Int 10 for 0-level spells, Int 11 for 1st-level spells, and so forth). The Difficulty Class for a saving throw against a beguiler's spell is 10 + the spell's level + the beguiler's Int modifier. Like other spellcasters, a beguiler can cast only a certain number of spells of each spell level per day. The base daily spell allotment is given on Table: The Beguiler. In addition, you receive bonus spells for a high Intelligence score.
A beguiler need not prepare spells in advance. You can cast any spell you know at any time, assuming you have not yet used up your spells per day for that spell level. A beguiler's caster level is equivalent to his class level.
Armored Mage (Ex): Normally, armor of any type interferes with an arcane spellcaster's gestures, which can cause your spells to fail if those spells have a somatic component. A beguiler's limited focus and specialized training, however, allow you to avoid any chance of arcane spell failure as long as you restrict yourself to light armor. This training does not extend to any other form of armor, nor does this ability apply to spells gained from other spellcasting classes.
Trapfinding: Beguilers can use the Search skill to locate traps when the task has a Difficulty Class higher than 20. Finding a nonmagical trap has a DC of at least 20, or higher if it is well hidden. Finding a magic trap has a DC of 25 + the level of the spell used to create it.
Beguilers can use the Disable Device skill to disarm magic traps. A magic trap typically has a DC of 25 + the level of the spell used to create it.
A beguiler who beats a trap's DC by 10 or more with a Disable Device check can study a trap, figure out how it works, and bypass it (with his allies) without disarming it.
Cloaked Casting (Ex): Starting at 2nd level, a beguiler's spells become more effective when cast against an unwary foe. You gain a +1 bonus to the spell's save DC when you cast a spell that targets any foe who would be denied a Dexterity bonus to AC (whether the target actually has a Dexterity bonus or not).
Advanced Learning (Ex): At 3rd level, you can add a new spell to your list, representing the result of personal study and experimentation. The spell must be a sorcerer/wizard spell of the enchantment or illusion school and of a level no higher than that of the highest-level spell you already know. Once a new spell is selected, it is forever added to your spell list and can be cast just like any other spell on your list.