Beyond Branching: Dialog Game Mechanics
Text-based games have been around since the 1960s, expanding and evolving into MUDs (Multi-User Dungeons) and other popular interactive fiction formats. These games captures the hearts and imaginations of users, and their mechanics can still be seen in games today.
Dialog interactions are present in the majority of games developed in the past two decades. These interactions deepen immersion and give a greater since of investment in the story and game itself.
Most of these dialog interactions, however, only use basic branching. Dialog branches form a dialog tree of different explicit choices and results. In a basic tree the step from one choice to another is deterministic without consideration of any other outside elements.
All dialog that uses this approach has the same basic mechanic: select the correct options in order to get your desired result. While this is sufficient for many games, going beyond branching dialog can create a wealth of dialog mechanics that create compelling, complex, and varying dialog interactions and puzzles.
Playing with Their Emotions
We’ve written about database driven digital humans before, with tracked emotional states using both binary emotions and emotional ranges. Not only can these emotions act as a driving force in varying dialog from the characters, but it can also be used in the creation of dialog puzzles.
At the most basic level, a requirement for progression can be locked behind an emotional state; perhaps a character needs to be very angry with the player to be prompted to attack them and cause a needed scuffle, or maybe the player must cause the NPC to trust them while also feeling anxious about their situation to get them to follow the player.
While these emotional states could be mapped out in a dialog tree, any interaction requiring multiple steps quickly causes this tree to balloon in size, with many repeated lines required. This gets exponentially worse with each increased dialog depth.
Instead of navigating up and down the tree with each choice, all choices can be kept at the same level and assigned an amount of influence for each emotion. Thus, the emotional state is tracked and modified with a minimal amount of writing until the character reaches the required state and the progress can be enacted.
This can be particularly valuable when accepting natural language input, as emotional states can be modified with positive or negative intents without requiring specific wording or phrases.
Keeping Score
Similar to tracking emotional states, a counter can be used to track the number of correct choices made or even the order of the choices made. Thus, a score can be kept across interactions with one NPC, multiple NPCs, or even combined with other events. For example, perhaps the head of a village will only help the player if they prove they have the best interests of the village in mind. This “best interests” can be proven by performing six acts of good that benefits the village, from slaying the local monster eating cattle to comforting a widow.
With a total score being kept, there can be far more than six good deeds choices provided and allow the player to approach the ones they feel are most compelling. This also supports extendability and modifications to the deeds, as they each only affect one variable.
Similarly, if the player needs to select a set of options (e.g. up, up, down, down, left, right, left, right, B, A), a tree would have to have fail states at each depth or even a tree with 10 depth and dozens of incorrect states and one successful state. Instead, a list could be added to during each attempt and then checked against a master list with the required order.
Emotional Labor
For many people, conversations with strangers can be draining. In the same way that mana is often a resource used to cast spells, similar resources can be used to conduct player’s conversation choices.
Having limited conversation resources creates an additional strategic element in how players must approach conversations. Conversations can be even be treated like battles, with their own combat mechanics, from limited resources to combinations and weakening defenses.
Reducing dialog choices due to emotional resources or similar mechanics not only creates puzzles for a player to solve, but can be used to communicate additional meaning via the limitation of choices.
A Selection of Topics
The Elder Scrolls III: Morrowind captured the hearts and imaginations of many gamers when it was released in 2002. Its expansive world and rich story were applauded by critics and fans alike.
One aspect of Morrowind that was rather unique was its topic based dialog. When interacting with a character, there were a selection of topics available that you could discuss with them. New topics appeared as you made discoveries and some topics hid quests and other engagements.
Dialog topic options can not only be hidden behind story unlocks, but by interactions with characters as well. For example, in a murder mystery game with an inventory, a player may have to show a particular item to a character to open an interaction. This blending between dialog systems and other game systems increases immersion within the mechanics of the game, while adding additional layers to interactions with characters.
There are many more game mechanics that go beyond branching dialog systems. Approaching game dialog with consideration of social interactions and game mechanics that are traditionally outside of dialog creates a new range of possible conversation gameplay.
