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Designing for Predictability

Predictability is a critical key to any design. If a map requires a specific behavior, then the forger must be capable of guaranteeing that behavior, lest the map eventually break during game play. Predictability is the ability to know what rules apply and what results are guaranteed for each set of circumstances.

A Forger Must Know His Tools

Bungie has handed forgers a set of tools to forge maps with. The forger must understand how to use those tools and what those tools will produce for them. Understanding exactly what each tool will yield in the form of game play experience will enable the forger to use the correct tool for each job.

But this doesn’t mean that the forger has to know the code level detailed workings of each tool. For example, the forger does not need to know how the spawn engine works at each nut and bolt under the hood. To establish a solid level of predictability, the forger must simply understand the intended uses for each tool and how to use them fully, properly, and effectively to achieve those intended uses.

An Example – Limiting A Team’s Respawn Area

If you want the blue team to respawn exclusively on the north half of a map, you would never cover the north half of the map with the Weak Respawn Zone for the purpose of achieving that goal. If you did that, you would fail. That is not the right tool. It was not designed to guarantee regional spawning of a specific team.

Instead, you would use the Respawn Zone (referred throughout the remainder of this document as Strong Zone). It was designed specifically with this intended use in mind. It is the proper tool for this job. Using the Strong Zone can be used to form a solid guarantee that the team it is assigned to will only spawn within the zone.

Knowing A Tool’s Requirements

To continue along the lines of the previous example, there are some factors to consider when using a Strong Zone. Respawn Points must be laid out on the map to prevent line of sight (LOS) from overcoming the Strong Zone. The Stock Pile Drop Zone must not extend a team’s Strong Zone region over Respawn Points that are not intended to be included in the team’s Strong Zone. And the layout of Respawn Points within the Strong Zone must ensure that regardless of any game time combination of simultaneous obstructions of the Respawn Points, enough of them will always remain available to respawn the entire team if necessary. Then, when all factors are taken into account and properly designed into the map, the forger can be certain where a player will always and will never spawn on the map. This is predictability.

We Know Enough Today

As we saw in the example above, predictability does not require knowing specific weights created by each and every influencer, or how many times a Strong Zone is stronger than a Weak Respawn Zone. While even I have argued that Bungie must give us every bit of detail we could ever think of, these arguments have proven hollow to the practical application of the tools themselves. The only thing that a forger must learn is what tools are available to him, what they were intended to accomplish, and what each tool requires (if anything) to function to its fullest potential. With that – and only that – information, the forger can then apply the tools appropriately and fully guarantee the game play experiences that they desire to achieve.

A Much Different Example – The Weak Respawn Zone

A Weak Respawn Zone adds very little weight to the Respawn Points within it. For this reason, there is no guarantee that those Respawn Points will be selected by the spawn engine. But that type of guarantee, as we saw earlier, is provided by another tool. The Weak Respawn Zone does not force or confine the respawn of players, but it favors their respawn.

This favoring is actually not random. If no dynamic influencers are present, the Respawn Points within the Weak Respawn Zone will be used every time over those outside the zone, simply because their weight is a little higher. Introduce dynamic influencers, and Weak Respawn Zones give the game play experience of “favoring” those Respawn Points within. The predictive model would simply state that a player has a greater affinity to respawn in the Weak Respawn Zone than outside it. Knowing this, the forger can utilize the Weak Respawn Zone over areas where he would prefer they spawn, but allow the spawn engine to use other Respawn Points when necessary.

Some people may say that this is not predictability at all. But remember, making an outcome predictable is making an outcome occur to a degree that we want to have it happen, not necessarily have it happen every time. If we want a specific outcome to be a team to respawn within a zone every time, then the correct tool is the Strong Zone. If we want a specific outcome to be a team to respawn within a zone more often, but let the spawn engine choose when it considers the area too dangerous (due to negative influencers), then the Weak Respawn Zone becomes the correct tool.


Learning what the various tools are for and how they were intended to be use will help the forger apply them correctly and effectively. This in turn will give the forger the ability to form predictive modeling of the game play with complete accuracy. Some predictions will be hard guarantees. Others will be generalizations of how the game play will flow. But they are all predictions that can be shown accurately demonstrable during game play – every time.