Neverwinter Nights 2: Sawyer on Familiars

From the official forums:

The oft-neglected familiar can be a fun pal in D&D. We (meaning Brock) have been working hard to make them be all that they can be. Our first pass at implementing familiars was received less than enthusiastically by QA. We went back to the drawing board, cut the familiars in half, stuffed their guts with ioun stones, and arrived at this implementation:

• Familiars are available to wizards and sorcerers at character creation. These are the available critters:
  • Bat: Master gains +3 to Listen checks.
    [li] Beetle: Master gains +1 hit point per level.
    [li] Cat: Master gains +2 to Move Silently and Hide checks.
    [li] Pig: Master gains +3 to Diplomacy checks.
    [li] Rabbit: Master gains +1 bonus to all saves.
    [li] Rat: Master gains +2 to Fortitude saves.
    [li] Spider: Master gains +3 to Bluff checks.
    [li] Weasel: Master gains +2 to Reflex saves.

  [li] The bonus granted by the familiar is only active when the familiar has been summoned.
  [li] Familiars can be summoned or unsummoned by the master at any time. If a familiar is unsummoned before dying, it can be summoned again without penalty.
  [li] If a familiar is killed, the master immediately loses the bonus provided by the familiar, has -2 to Con for the next 8 hours, and cannot summon the familiar again until after resting.
  [li] The player of the master can take direct control of the familiar. While under the master's control, the familiar has very limited capabilities. It cannot manipulate objects in any meaningful way and cannot speak to people (duh). It is capable of walking/running around, entering and exiting stealth mode, and being used as a conduit for the master's touch-based spells.
  [li] If a familiar goes more than 25' from the master, an effect plays on it that indicates it is reaching the maximum extent of its master's control. If the familiar goes more than 30' from the master, the master's control is severed. Control is forced back into the master and the familiar runs back to the master immediately.

Familiars can't go in backpacks, but they can be summoned/unsummoned pretty easily. They can also be commanded like other party members with the broadcast commands, so you don't need to take direct control of it if you want it to stop or follow.

No, familiars cannot attack on their own. The only way they can initiate an attack is by being a conduit for a touch spell from the master.

They didn't like not being able to control their familiars, especially since the familiars are so fragile. By allowing direct control and allowing touch spells to be cast through them, their viability and usefulness went way up.