The following class originally appeared in Dragon #280. It is © 2001 Dragon Magazine, WotC and author Monte Cook.

     The Eldritch Master is an arcane spellcaster who gains their power by bargaining with a powerful outsider... good or evil. They are usually loners, avoiding other arcane spellcasters.

Skills: Knowledge (Arcana) 8, Spellcraft 6, Diplomacy 2, Intimidation 2
Spellcasting: Must be able to cast arcane spells.

Special: The eldritch master must have made a bargain with some powerful otherworldly entity. In exchange for teaching the
    character, the entity must be rewarded with a task, a great magical treasure, or some special payment determined by the DM.

 

Level
Attack+
Fort+
Ref+
Will+
Special
Spells Known
1
2
3
4
5
1
+0
+0
+0
+2
Detect Magic, Combined Levels
+3
--
--
--
--
2
+1
+0
+0
+3
True Spell (0th)
+2
+2
--
--
--
3
+1
+1
+1
+3
Metamagic Feat, Spell Boost
--
+2
+2
--
--
4
+2
+1
+1
+4
Spell Dilettante
--
--
+2
+2
--
5
+2
+1
+1
+4
True Spell (1st)
--
--
--
+2
+2
6
+3
+2
+2
+5
Powerful Presence, Spell Boost, Metamagic Feat
+3
--
--
--
--
7
+3
+2
+2
+5
True Spell (2nd)
+2
+2
--
--
--
8
+4
+2
+2
+6
Knowing Stare, Spell Dilettante
--
+2
+2
--
--
9
+4
+3
+3
+6
Metamagic Feat, Soell Boost
--
--
+2
+2
--
10
+5
+3
+3
+7
Mastered Name
--
--
--
+2
+2

Skill points at each level: 4+Int modifier

The Eldritch Master's class skills and their key abilities are: Alchemy (Int), Concentration (Con), Craft (Int), Diplomacy (Cha),
    Intimidate (Cha), Knowledge (Any) (Int), Listen (Wis), Profession (Wis), Scry (Int), Sense Motive (Wis), Spellcraft (Int), Spot
    (Wis)

HD: d4

Weapon and Armor Proficiencies: Eldritch Masters are proficient no weapons, armor or shields.

Spells Known: These are bonus arcane spells known to the character, gained as a sorcerer gains new known spells. These are
    not bonus spells added to the total number that the character may cast. The character must already be cast spells as a sorcerer to
    benefit from these extra spells known (such as a sorcerer or bard). A character cannot benefit from bonus spells known if he
    cannot cast spells of that level.

Detect Magic (Sp): At will, the Eldritch Master can detect magic. This ability duplicates the spell of the same name with the class
    level used as caster level.

Combined Levels (Ex): The Eldritch Master may add his class levels to the number of levels in any other arcane casting class to
    determine level dependant effects.

True Spell (Su): The Eldritch Master may choose one spell of the listed level or lower as a True Spell. This spell may be cast
    1/day in addition to any spells per day the character may have. Once chosen, the choice cannot be changed.

Metamagic Feat: The Eldritch Master gains one free metamagic feat.

Spell Boost (Ex): The eldritch master gains the ability to cast a spell one level higher than his current highest level spell once per
    day. The Master also gains a spell of that level if he does not already know any spells of that level.

Spell Dilettante (Su): The Eldritch Master may choose a another classes spell list to learn spells from. Once a class has been
    chosen it cannot be changed. Even if the spell list is divine in nature, the spells are arcane spells when cast by the Eldritch Master.

Powerful presence (Su): The Master gains +2 to Diplomacy and Intimidation checks. Once per day as a standard action, he can
    force all living beings within a 30-foot radius to make a Will save DC 10 + class level + Cha bonus or suffer a -2 morale penalty
    on attacks, saves, and skill checks for 1 round/class level.

Mastered Name (Su): The Master gains the baility to know when another speaks his name. When they dom the Master knows
    the exact location and name of the speaker. This awareness is sufficient to allow scrying as if he had just met the speaker (DC 10).
    It does not convey enough knowledge to allow the Master to immediately teleport to that location, but that information can be
    gleaned by other means such as scrying.