The forces of Chaos are somewhere between good and evil, flesh and spirit, science and magic; they are madness incarnate.
The Cataclysm of the ancient times gave rise to a horror from the depths of the void, which poisoned the flux that flowed forth from the Fallen Star that had brought it to this world. The region where it fell has been reduced to barren wastes, populated by mutants, goblins, and madmen. In some places, there is a loose sense of civilization; the tribal Orcs, Goblins and Kobolds have made something of a life in the wastes, but none of these could be called truly sane. All sorts have suffered the effects of exposure to the energies of the wastes; among the armies that frequently arise there one might find what was once a nimble Elf fighting alongside what little remains of a once-proud Dwarven hero, with shattered spirits, fire in the brain, and bodies disfigured beyond recognition.
The forces of Chaos are unpredictable- indeed, not even those who would seek to control them can be sure of what they are dealing with. Many of the corrupted beings available to a would-be general of a Chaos army are unstable mutants with rapidly changing physiology, and indeed psychology. Mad science has added its part to the weird brew that is the domain of Chaos, creating even more horrific monstrosities; and not even the lower planes are immune to the effects, for the Chaos has been known to claim even hell-spawned demons. In the wastes, nothing is spared; knowledge is a stimulant, blood is money and the very fabric of life and logic are given over to mayhem.
Chaos has many luck-based and unpredictable cards around it, but a closer examination will reveal that this domain eventually reveals that it generally relies on the player's hand, while another part of it focuses on terrain alteration, mainly swamp. Faceless Lord is one of the two creatures that gives domain, allowing it to do some damage to the opponent and able to retreat if the player needs to preserve their domain. Crush of the Unknown, Rebellious Serfs, Twisted Nomad, and Summoning Circle are all meant to catch an opponent off guard or simply back up an assault. Reoccurring Dreams, Unstable Reality, and Gleb's Scavenger Hunt can easily disrupt a well planned strategy, forcing players to rethink their moves. Cards like Abyssal Bloodhound, Kobold Squatters, and Scavenge are useful, but only if there are ruins are present.
Early Game, you'll find that you have the biggest variety of start options. You can deploy a Drunken Mortar Team and hope that it can easily demolish whatever it finds, pull out a Seething Archosaur and watch your opponent try to get creative without it dealing 2 extra damage upon death, or send out a Glub Bird that's hard to hit. Defection is a tempting offer, but it's not always worth it, so treat it like getting an extra weenie if you need to rather than risking flux for a big creature. Furnace of Gibil, Mud Shelter and Quorum Stone make good quick building drops if you can maintain them properly until you get better methods of controlling your target location. Or if you're a bit more daring, use Gaze of the Tyrant and grab a flux well with that instead. Use Interference to take care of any pesky enchants at this point.
Mid Game just makes Chaos even crazier. You can now strike at the opponent's base with just Crush of the Unknown, but it's worth risking a Twisted Nomad if it's just for deploying a Rebellious Serfs. The Serfs are powerful enough to limit a straggling enemy player with a weenie to help. Noggel'n Bobbel'n makes a good card for a retreat. Kobold Warparty can do much damage if it has a proper supply of health-gaining cards and Kobolds from Early Game. Errant Enchantment can steal an enchant for you, and it's a decent creature on it's own as well. Redpeak Bandit can compromise the opponent's benefit he has from flux wells, and 1 flux can mean the difference between getting a domain this turn or next turn in some situations. Rat Rifle is great for dealing damage that opponents can't counterattack against, and Piked Heads and Direwood make strong defenses if used correctly.
Late Game gives Chaos access to powerful cards like Lower Plane Aberration and Prince of Desolation, but it can also disrupt strategies at this point with cards like Reoccurring Dreams, Vortex, and Gleb's Scavenger Hunt. Psychotic Break is a good way to deal with a big enemy creature that just spawned at the opponent's base. Scum Shambler is a cheap but powerful creature that can easily rip apart borders with Slime Child enchanted on it. Overall, try to mind game with your opponent a bit and deploy the Big Guns like crazy: Chaos has a good selection of cheap 3 Domain cards.
Keep an anti-enchant ready whenever you can; Chaos is crazy about enchantments. Keep a few creatures back at base to knock away the pesky cards that spawn through Summoning Circle, Crush of the Unknown, and be wary of thief cards that will want to steal from your deck, creatures, and flux like Snooping Goblin and Mind Transplant. Explore aggressively, as Chaos players will often drop a building at some point in early game. Don't despair if your opponent reaches 3 domain, as it's normally pretty easy to destroy at least one of the domain sources in some way, although smarter players will try to defend the weaker source. Keep an eye out for unorthodox control attempts like Gruult Caverns and That Hive. And don't let too many ruins appear on the field, or Abyssal Bloodhounds and Kobold Squatters could be running your way.