There are five main mechanics in the game: Time, Food, Sleep, Money, and Wanderlust. Each are described below.
Time progresses through the game in four Time Segments: Morning, Afternoon, Evening, and Night. Four Segments make up one day.
The game is built around the assumption of maintaining a four-Segment pattern, though systems are in place to stretch beyond that as necessary, as described below.
Each Time Segment is uniquely displayed in the game world with different time-of-day lighting, and certain Events are only available at certain Time Segments. Similarly, most Events consume one Time Segment.
Time Segments are only progressed through Events. The amount of real-world time the player spends in any one area has no bearing on the progression of Time Segments.
Food represents one of the most basic human needs for energy. On the user interface, it is presented as a horizontal Hunger Bar separated into six Hunger Segments. Each Hunger Segment is uniquely color-coded, with the left-most segment being a dark red, and the right-most segment a dark green, and other colors in between.
Each Hunger Segment correlates to one Time Segment - every time a Time Segment is progressed, a single Hunger Segment is consumed, from right to left. If multiple Time Segments are progressed simultaneously (such as through some failed Minigames), then a proportional amount of Hunger Segments are consumed as well.
Additionally, some Events can also consume additional Hunger Segments, unrelated to the progression of Time Segments.
If there are no more Hunger Segments in the bar, meaning the bar is completely empty, and a Hunger Segment is to be consumed, then the player loses the game - Rachel passes out, a Good Samaritan takes her to the local hospital, where they learn she is from Arcadia Bay, to which she is returned.
Below the Hunger Bar is a horizontal list of Food Stores. Each Food Store is a pictogram roughly representing what the item is supposed to be (a candy bar, a take-out box, etc) as well as a number representing how many Hunger Segments that Food Store replenishes.
At any time between Events, the player can click on any Food Store to immediately consume it, restoring the presented number of Hunger Segments (up to the maximum of 6 Hunger Segments) and losing that Food Store in the process. Food Stores can be consumed in any order - they do not need to be consumed in the order they are listed.
Hovering over a Food Store will present a preview ghost of the changes that consuming it makes. Most of the time, this is simply an increase in Hunger Segments, but some Food Stores may also affect Sleep and even Time, which will also be presented in the preview ghost.
Both Hunger Segments and Food Stores are replenished through certain Events. Most Events replenish neither, some replenish one or the other, and others replenish both. As with most Events, those that replenish Hunger Segments and Food Stores often transactional, offering replenishment in exchange for money, sex, or even Time Segments.
Sleep represents the other half of the basic human need for energy. On the user interface, it is presented as a horizontal Energy Bar separated into six Energy Segments. It is color-coded the same way as the Hunger Bar, just with the color-coded reversed due to its placement on the right side of the screen - the deep red is on the far-right segment, and the deep green on the far-left segment.
Much like Hunger Segments, each Energy Segment correlates to one Time Segment, and are consumed from left to right (again a mirror from the Hunger Segments). Energy Segments are consumed as Time Segments progress, and certain Events can consume more Energy Segments independent of Time Segments.
If the Energy Bar is empty when another Energy Segment is to be consumed, then it results in the same fail state as running out of Hunger Segments.
Below the Energy Bar is a horizontal list of Energy Stores, which are pictograms roughly representing what they are (an energy drink, a caffeine pill, etc) as well as a number representing how many Energy Segments that Energy Store replenishes.
Energy Stores function identically to Food Stores. Unlike Food Stores however, they tend to be far more stratified: the common Energy Stores replenish less Energy Segments than the common Food Stores tend to, and the more powerful Energy Stores tend to have more extreme penalties than the more powerful Food Stores do - Energy Stores negatively affecting hunger and time are far more common than Food Stores negatively affecting the other mechanics.
Both Energy Segments and Energy Stores are replenished through certain Events. The replenishment of both is privy to the same caveats as the replenishment of Hunger Segments and Food Stores.
Money is the ephemeral tie that binds. A requirement behind which many Events are locked, and the consequent of many Events more, having a steady reserve of Money is crucial for smoothly traversing through the game world.
While it is viable to constantly alternate your Operations with working to get money, and effectively living job-to-job, the time restrictions of certain Events may make it preferable to instead focus on building up a supply of Money in a Location that has ample opportunities for making Money. It is worth keeping in mind, however, that staying in one place too long can trigger Wanderlust to force your hand.
Money is presented as a simple numeric counter. Many Events are only available if the player has enough Money for them, which is consumed in the transaction. Similarly, Money is replenished through Events. Many Events that provide Money consume only Time (and implicitly Hunger and Energy), though many more lucrative Events will exchange sex for Money.
Wanderlust represents Rachel's innate flightiness, and her inability to stay put for too long. A mechanic that is typically hidden from the player, it only becomes apparent if the player engages four or more non-Travel Operations in a row.
When this mechanic is apparent, it represents itself as a segmented vertical Flight Bar along the bottom-left of the screen. Unlike the Hunger Bar and Energy Bar, which each have six segments, the Flight Bar is separated into ten Flight Segments. Also unlike the other bars, the Flight Bar starts out empty, and fills up with Flight Segments with the progression of Time Segments. It is color-coded with dark green at the bottom, and dark red at the top.
If the Flight Bar comes fully filled, then all non-Travel Operations become unavailable to the player - their only option to progress the game is to take a Travel option. There are no exceptions to this limitation: even if the player's Hunger and Energy bars are empty, and they have no Food Stores or Energy Stores or Money, they are still forced to Travel. This can result in a guaranteed fail state, if either the Hunger or Energy Bars are depleted before the Travel operation.
Wanderlust is automatically reset to zero, and the Flight Bar hidden, as soon as the player performs a Travel Operation.
There are certain unique non-central Gameplay Loops that temporarily disable Wanderlust.