Thursday, August 26, 2021

Locational Mapping and Timed Events

This is an article related to the creation of gamebooks but it applies equally to other mediums for interactive storytelling.

Locational Mapping and Timed Events

Locational mapping is a technique used to describe a geographical region, like a dungeon divided into rooms or a set of forest clearings connected by paths. The style exists to allow free, repeatable exploration of the area’s locations.

In locational mapping, the player may repeatedly read the same entries to simulate navigating back and forth between locations. Veneers parse the one-time events local to each location, so that returning to a location doesn’t feel like entering a time loop.

To talk about timed events in locational mapping, we must first revisit the concept of veneers.


If a one-time event can occur in a location, the first entry for that location is a veneer that checks the state of that room (asks for an event code) and directs the player to whichever entry describes the correct state of that location.

Example. The protagonist is in a room with Four Doors.

By going east, the protagonist reaches the intervening East Door Veneer that checks for an event code. The player hasn’t noted that event code so is routed to the Pre-Fight East Room, where an ambush occurs. The protagonist fights the monster and gets the room’s event code. After the fight, the protagonist can explore (the Post-Fight East Room), then return to the intersection of Four Doors.

Later, the protagonist returns to the room with Four Doors and goes east again. This time, when the East Door Veneer asks for the event code, the player has it noted; the veneer now points to the Post-Fight East Room, skipping the fight.


Locational mapping has difficulty with timed events. This problem appears in several ways and has several possible solutions.

Imagine this scenario. Wandering through a woodland, the sun sets when the protagonist reaches an entry representing the middle of the forest. However, the area’s locational mapping layout means the protagonist may leave and later revisit that location. Because the location’s entry describes a sunset, the sun sets each time the protagonist goes there.

A player might ignore the repetition if the sunset only has a story effect. Sure, the rising tension is diffused by the repeated experience, but story timing in locational mapping inherently bows to the player’s chosen pace of exploration. Bigger problems occur when the player must deal with an important story event or a mechanical change.

For example, if the sun sets, the protagonist must thereafter deal with mechanics related to darkness. If the protagonist returns to the earlier locations of the forest, does darkness apply? Should it only be nighttime in half the forest?

Solution 1: No Timed Events

If the story isn’t one with a deadline, you can completely omit the notion of time passing, putting such events before the story transitions into locational mapping or after it transitions back from locational mapping. The protagonist isn’t trying to catch up with a kidnapper and has no one waiting on the far side of the forest; it doesn’t matter how long things take.

The drawback here is that unlimited time is non-immersive, and exploration without timing lacks an essential tension. It also reduces replayability; the player has already seen every location in the area.

Because I write for D&D characters, I’m also concerned about balancing difficulty when the protagonist has unlimited resting potential. To some degree, I can balance unlimited rests with a chance for a random encounter; resting has a chance to be counter-productive.

Solution 2: Bottleneck

Halfway through the forest, the sun sets at a “bottleneck” location. This entry serves as a one-way door separating the earlier locations from the later locations. No post-bottleneck location gives an option to return to any pre-bottleneck location (or to the bottleneck itself). With the sun having set, the post-bottleneck locations all have darkness penalties.

The disadvantage of this method is that the protagonist can no longer return to earlier areas. Many players want to see as much as possible, exploring every room, and may not like stumbling past an arbitrary point of no return. Therefore, the bottleneck should include a one-way environment the player can choose to engage with. Climbing down a cliff, getting on a raft and going downriver, or passing through a door that has no handle on the other side are good examples. There should be some signal that the player won’t be able to explore areas that were left behind.

Solution 3: Brute Force

The adventure tracks time separately. For example, the player is instructed to make a hashmark each time a location is entered, until 15 marks are tallied, after which the sun sets and darkness mechanics apply everywhere. This instruction occurs at the start of the locational area and requires the player to apply the mechanics without being prompted by each location’s text.

The disadvantages here are several. The player must meticulously track time, must notice when the timing threshold is reached, and must remember (or have noted) the new mechanical effects. It’s a lot of note-taking.


The following approach is a version that incorporates multiple techniques. It’s from an upcoming book in the Eight Petals Argent adventure set. [Map by Dyson Logos, with some alterations.]

The map below is color-coded. If you can’t distinguish these, the northwest-clustered routes are blue, the north-central-clustered routes are purple, and the southern-clustered routes are red. The green northeast cluster is the smallest (destination) cluster.

The protagonist is leading a column of mercenaries and supply wagons east through a jungle. The only river crossing is on the far side of an abandoned, overgrow city. The protagonist will enter from the northwest (blue route cluster) or from the south (red route cluster), depending on a major split chosen in the prior chapter. The goal is to reach the river-crossing in the northeast corner of the city. An army of zombies is slowly sweeping eastward after the group.

The initial roadways can be explored freely within their clusters (red or blue). However, at any intersection that transitions into the purple cluster, the description of that area includes a clear view of the approaching zombies. The threat is still distant but it justifies me not giving the option to return to the earlier cluster, back toward the undead. The caravan must progress toward the bridge to stay ahead of the threat.

No Timed Events: I don’t use descriptions mid-area to describe timed events. The sun doesn’t set at any point, nor is the city overwhelmed by the approaching zombies. The zombies don’t take the city until the protagonist is over the river and out of the locationally-mapped area.

To maintain some tension, I still describe the approaching undead. But these descriptions are vague. The real events won’t occur while the protagonist is inside the locationally-mapped area.

Bottlenecks: I don’t let the player return to an entry cluster after getting to the purple routes. These intersections aren’t technically bottlenecks. The protagonist doesn’t necessarily have to visit a particular one of them and can revisit those intersections. However, I do use those points to prevent backward travel. Instead of timed events adding tension, the player can see the zombies while in those intersections, looking down the long streets of the city. There is a repeatable reminder of the threat there. However, the zombies are always approaching, never arriving. I simply use these transition points to omit the option to go backward toward the threat.

Tracking Time: I don’t track time, per se. But the protagonist has a limited number of soldiers. Ambushes occur on some roads, costing soldiers. Although the column can return along some of those roads safely (using veneers), each loss of soldiers represents a countdown until the mercenary company is depleted to a minimum number that is checked periodically. Excessive exploration means more encounters and fewer soldiers. Reaching the minimum company size ends the chapter immediately in an unfavorable way.


Locational mapping allows the protagonist to choose the order of exploration, perhaps missing some areas, thus granting greater agency to the player. The right tools let us provide this experience in ways that don’t read as redundant or risk the protagonist falling into a time loop. Although it can be harder to create, locational exploration is one of the joyous parts of a good gamebook. It should be embraced whenever and however you can make it work.