Warlock:Abilities and General

Ability Scores

 * Strength: Not generally needed.
 * Constitution: Depending on your choice of pact, this may be your primary or tertiary stat.
 * Important for Fortitude defense, hit points, and healing surges.
 * Dexterity: Not generally needed.
 * Intelligence: Generally your secondary stat.
 * Important for AC and Reflex defense. Minimum of 13 needed to pick up Ritual Caster.
 * Wisdom: Not generally needed.
 * Charisma: Like Con, this ranges from the primary to tertiary stat.
 * Important for Will defense and useful for social skills.

Pacts

 * Dark Pact (FRPG): primary Cha, secondary Int.
 * Pact boon: chance to deal damage to enemies who attack you.
 * Powers utilize several 'sacrifice allies to hurt enemies', although not all do. Not an optimal choice.
 * Fey Pact: primary Cha, secondary Int.
 * Pact boon: teleporting the character.
 * Powers have a high proportion of Psychic keyword, and high movement capabilities.
 * Infernal Pact: primary Con, secondary Int.
 * Pact boon: temporary hit points.
 * Powers tend to be more damage-oriented than other warlock pacts. Focus is on taking hits.
 * Star Pact: primary Cha and Con, tertiary Int.
 * Pact boon: re-roll dice.
 * Powers specialize in debuffing enemies.
 * It's possible (and perhaps recommended) to focus on either Con or Cha and have the other be a secondary stat. These warlocks are likely to take some powers appropriate to their primary ability from other pacts; the Twofold Pact feat can be used to gain pact-based benefits from those powers as well.

Role
Warlocks are strikers, which means high damage, high mobility, and good out-of-combat utility.

They have the arcane power source, which grants them some controller abilities.

Of all strikers, Warlocks generally produce the lowest damage output. Warlocks can emphasize damage to try to maintain the damage level of other strikers or they can worry less about damage and utilize the control aspects in lieu of damage. Both are viable strategies.