This article concerns Halo 3's Forge map editor. For full reviews of Halo 3 itself, check out our Halo 3 campaign review and Halo 3 multiplayer review.

If you're a Halo fan, by this point you have surely heard at least something about Forge, the map-tweaking utility Bungie is including out of the box with Halo 3. At first glance, it seems like a very limited tool. You cannot edit any fundamental map geometry, you can only place or remove various accoutrements such as weapons and vehicles, crates and other ornamentation, spawn points and objectives, and so on.

Don't trust that first glance, however--it only scratches the surface of what is truly available when you start to delve deep into Forge. Though, for obvious reasons, Bungie has chosen to limit the scope of your individual additions to the supplied standard maps, the combined effects of these additions in creative ways can produce maps and games that play radically differently than anything offered officially.

How, you ask? Read on.

Hammer and Anvil

Items can be rotated and stacked, and large simple objects like crates make for great building blocks. Many players will surely start off with simple tweaks like filling a map with rocket lauchers and grenades for a chaotic game, removing all excess weapons and ammo for a more conservative game, blocking doorways with large objects to alter the flow of a map, and so on.

By combining elements, such as placing a crate directly above a grav lift, you can create new unusual objects. A row of such combinations might create a floating, undulating "bridge" that could be used to get from one high perch to another. Taking that idea even further, one starts to imagine more ambitious ideals like a complex obstacle course such as one might see in a 3D platformer, with checkpoints placed at key areas along the set route.

Scrimping and Saving

For example, simple crates might cost only $2 each with a map limit of eight, while large Wraith tanks might cost $40 a pop with a map limit of two. Certain maps simply do not allow certain vehicles, for size reasons--smaller maps might disallow tanks entirely.

Overall budgets are in the range of hundreds of dollars, and you can always get extra cash by deleting extraneous decorative elements already placed on the map by default, so it does seem like there is a great deal of room for creativity before you start exhausting the practical limits.

Swiss Army Knife
One particularly clever placeable object is known simply as the custom powerup. On its own, the custom powerup is nothing but a blank slate. Its properties are actually determined in the custom gametype settings, which allows you to tie the same map to different gametypes while retaining different custom powerups for each depending on the needs of the gametype.

There's a lot to cover with this baby, so let's just get going. For one thing, you can modify the shield and health settings--how much damage resistance it provides, what shield multiplier it gives, if it removes the shield, if it raises or lowers shield recharge rate and by how much, if the player's shield recharges when the player causes damage, if the player is headshot immune.

Similarly, it can affect weapon stats--modifying damage caused from 0%-300% or even to insta-kill status, if grenades regenerate or ammo is infinite, if weapon pickup is disabled.

The powerup can raise or lower movement speed, adjust the pull of gravity to be greater or less, forbid or allow vehicle usage in different ways, modify the player sensor's range and ability to detect friends and foes, and even modify the player's physical appearance to be a different color, apply different levels of cloaking, or apply different types of waypoints to the player.

Batter Up
The obvious use of the custom powerup is of course as a coveted stat boost item, or even as a crippling curse cleverly placed in a highly-trafficked corridor to spice up a game of deathmatch. Of course, it can be used in much more unorthodox ways.

One custom user-made gametype mentioned by Bungie's Frank O'Connor, involves playing baseball with rockets (the balls) and gravity hammers (the bats) as well as checkpoints for bases; a special "batter" powerup might boost run speed and shields to give the player more of a fighting chance to make it around the bases alive.

Keep it Simple, Stupid
You don't need fancy stuff like the custom powerup to make some interesting custom games. Just with the gametype editor, you could easily devise any number of skill-pushing Slayer variants. For example, points might only be awarded for headshots, allowing you and your gaming group to hone your killer instincts before sticking it to the online matchmade players.

You might also work on your efficiency by detracting a point for every death, meaning the winner of the match will be the player with the highest spread between kills and deaths--sure, that statistic is tracked in regular games, but why not use it as a victory condition? The enormous amount of control over how points are awarded and in what quantity open up the doors to a wealth of simple but useful quick hacks.

So how can you take it further? Read on to find out.

It's in the Game
Where Forge really shines is when it is used in tandem with the extensive gametype customization options available in Halo 3. Multiplayer fans of Halo and Halo 2 (as well as Bungie's past games for those whose gaming memories extend further back than the current millenium) know that the studio has always prided itself on offering a variety of multiplayer gametypes and options. Halo 3 represents the most dramatic implementation of that philosophy yet.

You can change an enormous number of properties regarding the world, such as its gravity and spawn settings; players, such as the properties described in the custom powerup section above; win conditions and how points are awarded; and a huge number of gametype-specific options. Listing all of the submenus upon submenus would simply require too much space for this article, but suffice to say there is no shortage of choice.

In addition to standby gametypes such as Slayer, King of the Hill, Capture the Flag, Oddball, Assault, Territories, Juggernaut, and VIP, Bungie has listened to its community and added Infection--commonly known in Halo 2 friend circles as "Zombie," the unofficial gametype that converts "human" players to "zombie" players when killed by a zombie, until the last human is killed.

Each of these gametypes has a whole ream of options that can be tweaked, and if the type has geographical objectives, they can be adjusted and placed on any map through Forge. Capture zones can be placed and sized for Territories, hill zones can be placed in King of the Hill, go-to points can be placed in VIP games, and so on.

It Wasn't in the Game (But Now it Is)

By combining Forge and the gametype editor, you can craft new types of games unlike anything offered in the default lineup. One player came up with a mode that, in some ways, shares more in common with land-and-air games like Battlefield than with the Halo series.

In this mode, customized in Forge for a large outdoor map, each team has a randomly-assigned VIP player and an indestructible flying vehicle with room for two passengers. The two VIPs, who cannot pilot the vehicles themselves, must reach airborne checkpoints before the other team does, chaufferred by another teammate. Meanwhile, other teammates on the ground attempt to disrupt their enemies' checkpoint-grabbing progress by sniping the VIPs out of their passenger seats and protect their own VIPs by assaulting enemy ground troops.

With the baseball mode as an example, one could also imagine recreations of other sports, based on modes such as Oddball or VIP. By modifying maps and gametype objectives in Forge, the already-powerful gametype editor becomes all that more formidable.

Jump In

An impressive technical aspect of Forge is that other players can play around in your map as you edit it in real time, via Xbox Live; you can choose to let them join in the editing or remain as regular players. Creating very unusual and complex gametypes tends to require a lot of iteration, as developers and modders know, so having a group with whom you can jump in and out of games and serve as a live body of testers is invaluable for balance purposes.

Show the World

Of course you can share your creations with your friends through custom games, but Bungie wants to encourage polish and creativity by highlighting the best user-made content for the Halo community at large. You can recommend any content, whether it was made by you or others, to your friends, and Bungie will also be monitoring the content with the best user reaction and most recommendations, as well as content highlighted on community sites online, for its own "Bungie Recommends" website feature.

"Bungie Recommends" will showcase the best of user-generated Halo 3 content on a regular basis, and it will be part of what Bungie describes as its most extensive and ambitious game-to-website integration yet. The company has yet to fully unveil what all that entails (although we're promised the big reveal is coming soon), but in addition to the already-known screenshot and video sharing features it will also allow you to "tag" featured content you'd like to download. Impressively, that content will then download automatically to your Xbox 360.

Here for the Long Haul

Just as Halo 2 provided the crucial showcase Xbox Live needed, with its elegant lobby system and website integration, so does Bungie plan for Halo 3 to demonsrate how Xbox Live can be taken to the next level with Xbox 360. The franchise is already known for its online multiplayer longevity, but with Forge and a formidable gametype editor, not to mention promised downloadable content, Halo 3 will clearly have enough on the multiplayer side to stay fresh for the rest of this generation if not beyond.