|B| The Common Black Deck |B|
For those who like to live on the edge and ignore Karma, here is an all commons, type II straight black deck:

4 Drain Life
A must for just about any straight black deck. Nearly as efficient as the red X-spells for damage, plus bonus healing. Use on nasties you can't Banish/Terror, to finish off your opponent, or for last ditch healing.
4 Dark Ritual
A must for any deck that contains black. For Drain Life boosts to kill large creatures, a "Giant Growth" to save your Shades, and a quick hoard of early creatures.
3 Dark Banishing or 3 Terror
Underestimated by experienced players because of their limitations, but extremely useful against non-black decks. Sideboard out when playing against black.
3 Torture
Ever the anti-creature color, Torture adds another quick way to deal with pesky black creatures as well.
4 Unholy Strength
Creature enchantments on your own creatures are generally not a good idea because you are giving your opponent the chance to take out 2 cards with one. These may be a small exception. Go for the quick kill.

4 Frozen Shade
Another important part of this all black deck. Faster than Carrion Ants and not much use to a straight blue deck if copied or controlled. Given the choice between doing more damage to your opponent or playing more creatures, almost always do more damage. Better to make your opponent waste a Control, Wrath of God, or Earthquake now than give her more targets. Besides, how many opponents can survive the equivalent of a Fireball a turn?
4 Phyrexian War Beast and 4 Tar Pit Warrior
Who can argue against a first round Dark Ritual'ed 3/4? War Beasts are great for rolling over Dervish decks, and unlike the Statue, even works without land. Tar Pits, though vulnerable, may force your opponent to waste a card and at least can't be stolen.
3 Clay Statue
Useful for fighting off protection from black creatures and getting around CoP: Black... not to mention great defence.
3 Vampire Bats and 4 Skulking Ghost
Cheap flyers that can take out Specters by themselves, or Serras with just two, or one plus an enchantment. Very useful for fast kills.

20 Swamp
More land is not needed because of two reasons: mono-color decks have less trouble getting the correct colored mana; and none of the cards have over 4 casting cost.

|B| Deck Notes |B|

The strengths of this deck are that its creatures are almost on the weenie level, yet they can do significant amounts of damage without having too many on the table. Pumpable creatures versus Control and Mana Flare decks. Fast enough to take on weenies. Many of its power creatures are unaffected by Meekstone (another good reason to use Soul Kiss instead of Unholy Strength). The primary weakness of this deck is White. Hopefully, your artifacts will help block White Knights and their cousins, or to get around CoP: Black.

|B| Improvements |B|

Uncommon improvements:
3 or 4 Gloom
Probably the first uncommons you'll need. For friendly play, you might not need them, but definitely 4 are needed in a tournament sideboard to keep down CoP:Black and help prevent Karma from ever hitting the table.
4 Knight of Stromgald
Ice Age's answer to the Ebon Hand. Quick and efficient. Just 3 mana needed to take out Juggernauts. Never pump until after your opponent has declared blockers. You might need to save that mana to conjure something after the attack.
4 Dystopia
3 mana, 3 life, 3 of your opponent's permanents gone. An amazing sideboard card.

Retired cards:

4 Hymn to Tourach and 4 Order of the Ebon Hand
For a while during Fallen Empires, it almost seemed as if common decks were going to stand a chance against moneybag decks. Alas, it was not to be.
4 Hypnotic Specter
Once one of the most feared of first round Dark Ritual creatures. The powers that be decided it was just too feared.