It's hard to imagine two more dissimilar strategy games.

Where "Command & Conquer 3: Tiberium Wars" moves quickly, "Supreme Commander" takes its time. One is about grand strategy and careful planning, the other about rapid expansion and decisive blows.

But it's easy to like both.

'TIBERIUM WARS'

"Command & Conquer 3: Tiberium Wars" is by far the more accessible of the two, so we'll start there.

As in the previous games (not counting the various subseries), "Tiberium Wars" centers on the battle between several factions over Tiberium, a crystal that grows rapidly and causes mutation and death for Earth life forms exposed to it for too long. It's also rich in valuable elements and easy to refine, making it a ready source of wealth for both groups.

The first of these groups is the Global Defense Initiative, a military organization in charge of the Blue Zones, areas of Earth uncontaminated by Tiberium. The Yellow Zones, contaminated but still habitable, are the domain of the Brotherhood of Nod, a quasi-religious militant group led by Kane, a messianic figure who experiments with the mutagenic properties of Tiberium and has cheated death several times.

Each side has a specialty. GDI dominates with brute force; Nod are masters of speed, stealth and sabotage; and a third faction — we won't spoil anything — has a special affinity for Tiberium and a powerful command of the skies.

Veteran players will recognize the game play immediately. It has been slightly updated for the modern age (and the graphics have been gorgeously upgraded), but at its heart, "Tiberium Wars" is still about pumping out as many units as possible as quickly as possible and smashing the enemy in a lightning strike — at least, that's the way of online games. The single-player missions are a bit more involved, and are worth playing through. Gamers can choose between GDI and Nod campaigns at the start, with a third, short Scrin campaign opening up after the first two are won.

But the real treat is the cast that's been assembled for the live-action story scenes. Michael Ironside and "Battlestar Galactica's" Grace Park are on hand for the GDI, along with Billy Dee Williams, aka Lando Calrissian from "Star Wars." On the side of Nod are Josh Holloway from "Lost" and Tricia Helfer, also from "Galactica." And Joe Kucan, the man who has played Kane since 1995, appears eerily unaged.

It's all hokey in a good way, and seeing so many familiar faces makes it a treat to revisit this futuristic war.

'SUPREME COMMANDER'

Instead of humans and aliens, the futuristic wars of "Supreme Commander" are fought by robots. It's the player's job to build and maintain these robots.

A warning: The game's a beauty with a beefy machine, but the system requirements are very steep, and the game is designed to take advantage of multicore processors.

There's a bit of a plot explaining why the game's three factions — the United Earth Federation, the semi-robotic Cybran Nation and the mystical, alien-influenced Aeon Illuminate — hate each other and want to kill each other.

But at least they only kill each other on a one-on-one scale. That's thanks to the massive Armored Command Units that their warmongers tool around in, hulking machines with the ability to warp from planet to planet and build a city-sized base from scratch, then pump out legions of robotic soldiers, vehicles, aircraft and naval units.

And the scope of the battlefields is vast: Players can zoom the view into a satellite image festooned with abstract unit markers in a snap, and zoom down to a close-up view of the battlefield just as easily.

The cultures of this future have mastered transmutation and can use mass dredged up from resource-rich nodes and energy produced by generators to create anything they need, starting with basic units and structures, and progressing to two higher-technology tiers and a fourth experimental one. Aside from military units, factories can pump out construction helpers at each tier.

Mass is harder to harvest than energy is to produce, but energy can be converted to mass by special structures at a high cost. Running a deficit in either resource, or both, brings production to a crawl.

There's a trio of solo campaigns, one for each faction. They run the player through the mechanics of the game, but the real meat is in online play.

A crafty player can build forward bases in an enemy's blind spot to pump out tanks to keep the foe off-guard and contained. A desperate player can try to force a draw with a suicide run against the enemy's ACU, hoping to get close enough that the massive explosion that consumes a dying suit takes the other guy out as well. There are as many ways to win — or lose — a competitive round of "Supreme Commander" as players can think up.