The Emotional Experience of Interaction with NPCs in RPG Games

According to a survey in the book How Games Move Us: Emotion by Design, when asked "What moment in a game makes you want to cry?", the majority of players responded that, they feel like crying when faced with the death of NPCs fighting together with them. NPCs are one of the main sources of emotional experience for players as an object of emotional projection in games. How do NPCs bring players a deep emotional experience through their interaction with players in RPGs?

1. Believable NPC: in line with the expectations of players

First of all, the appearance of NPCs in game needs to meet players' expectations. If the behavior of NPCs and their interaction with players meet players' psychological expectations of the characters, the NPCs are believable, even if players know that this is not a real player playing. To make NPC believable, it must be consistent with players' expectations. These expectations can be classified into three levels with psychological research perspectives: physics, biology and psychology.

From a physics perspective, players expect animated and non-animated objects to follow what physicists call "naive physics", which involves our understanding of how the physical world works. For example, the movement of NPCs has a trajectory and does not appear out of thin air; NPCs are affected by weight, inertia, etc., and will collide with each other. These are the most basic principles that conform to the physics of the world,and the design in these aspects meets the original expectations of players. The magical creatures that resemble jellyfish in "Sky: Children of the Light" form a long line in the air to help the player go ahead of the road; the NPC Robyn in "Harry Potter: Magic Awakened" walking randomly in the library, will immediately turn around when she comes across any players. These are in line with the basic rules of the physical world.

The magic creatures forming a road for players in Sky: Children of the Light

From a biological perspective, the real creatures that appear in the game world give us a lot of natural expectations. When players interact with other creatures, whether they are new ones created in the game or portrayals of real creatures, we will evaluate these creatures based on our natural expectations. Psychologists refer to the results of these expectations as "naive biology". In the creation of game NPC creatures, the most basic expectations of biological systems should be met. For example, in the interaction with pets in Cyberpunk 2077, the feedback during the interaction is based on the reaction of those creatures after being touched and patted.

In order to meet players' naive expectations of the artificial characters, the social system in game can make feedback accordingly. In GTA, the game carefully designed the feedback of NPC to players, when the player goes into a new place, into someone's field of vision or does something to attract their attention, the player can get the corresponding feedback, such as greetings, complaining, swearing and so on. In this way, the player's game experience in this scene will be more vivid and interesting.

The interaction between player and NPC in GTA5

The NPC behavior in "Red Dead Redemption 2" is much richer, when a player walks into a room, the NPCs in the space will stare at the player, and will even take the initiative to talk. The reactions of NPCs vary from role to role, such as the gaze of a guest, the waving hands of a standing person, the greeting of a bartender, etc. These are realistic simulations of people suddenly barging into a room and attracting the attention of others, so the player's emotional experience will be better.

《Red Dead Redemption 2》

2. The background of NPCs: promoting the plot

Characters with unique personalities

NPCs are like friends in the game world, and they have different personalities, introvert or outgoing, stubborn or open, petty or friendly. Personalized and distinctive NPCs can bring players a vivid gaming experience and make the game world more immersive.

Cassandra in Harry Potter: Magic Awakened will say in a slightly contemptuous and mocking tone, "You're dressed so well for you - ordinary enough", making players want to change a new outfit. She reminds each of us of the annoying classmates that we have met in school.

The deepth of "evil"

In RPGs that focus more on stories, the emotional interaction between villainous NPCs and players is often more deeply felt. The "evil" of the villains are often motivated by the tragic character stories behind the NPCs, allowing players to understand their "evil" and generate emotional connections to the NPCs. In World of Warcraft, Arthas, a prince of noble birth. In order to defend his homeland, he was tempted to take up the cursed sword to defeat the demon Mal'Ganis. And under the impact of his strong desire for revenge, he fell into darkness step by step and became a death knight, and was finally killed under the attack of several allied forces. Arthas is a villain role, like those in ancient Greek tragedy, but also one of the most classic villain NPCs.

Arthas Menethil

The connections with the inner subconscious of players

What kind of characters do players want to "punish" in games? The most typical example is the zombie NPCs in some shooting games, which are villainous NPCs that destroy the world and disrupt players' mission plans. In terms of appearence, they are human-like monsters, so in the players' subconscious, killing zombies will give them a certain sense of accomplishment like "defeating".

3. The AI design of NPCs: creating a more realistic experience

Interact with players and help to complete tasks

The most common function of NPCs is to help players complete their tasks by acting as partners, friends, and even "teachers" in game. Fighting shoulder to shoulder with players is the most direct way to generate emotional experience with them, such as Pu Songling in A Chinese Ghost Story Online, as the player's "guide" in the game's tutorial process, for helping players to quickly get started in the game, as well as promoting the progress of stories.

NPC interacting with the scenes

In order to create a more realistic game experience for players, the interaction between NPCs and the elements in the scene also needs to be well designed. Even if they do not interact with players directly, the interaction of NPCs and scenes can form a more natural environment for players. In The Sims, after players interacting with NPCs, they will take their own actions according to the scene. For example, they will sit on a nearby chair, or lie down on a bed.

The Sims 4

4. The behaviour of NPCs: intensifying the emotional experience

Protection

"Sense of responsibility" is an emotional experience that is difficult to bring to audiences in traditional media other than games, and when the choice is put into the hands of players, the sense of responsibility arises. Because of the heroism that game backgrounds and game mechanics can easily create, protective relationships are often found between players and NPCs in games.

A very common case is the game ICO, players can hold the hand of a girl, who can help the player in some ways, through a simple mechanism like pressing R1. The girl is also very vulnerable, so much so that the player will be very worried about losing her. Holding her hand means that the player and the girl are together, and no matter what the situation, the player can protect the girl from harm. By simple mechanism "holding hands", the game created warmth, and this touching and healing scene did not need dialogue to express, but it provides the player with a deep emotional experience just through interaction between the player and NPC.

Cooperation

In recent years, there has also been an increasing trend in games where the players and NPCs are in a partnership, and this cooperative interaction can often be advanced through the game's plot, thus enhancing the player's emotional experience. Brothers: A Tale of Two Sons tells the story of two brothers who embark on a journey to save their seriously ill father, overcoming obstacles, making alliances, and saving others and themselves along the way. NPC, the huge and hideous giant, who looks like the Boss, always appears with a crying face because he has lost his wife, and looks forward to the two brothers to help him save her. For this reason, the giant and the brothers form a cooperative relationship. And the giant then provide a lot of help to the player, such as using his arms to build a bridge so the brothers can walk on it, and the two will help the giant to rescue his wife.

The giant in Brothers: A Tale of Two Sons

Competition

As a special type of NPC, enemies in game can also be a good trigger for emotions, when the competitive interaction with players is well designed. In A Chinese Ghost Story, through the plot, the tasks help players deeply understand the events in the village and the background of the love story, so that players accept the challenge and defeat NPCs one after another. In this process, players not only have a very high sense of participation, but can also actually upgrade their avatars, collect equipment and become stronger, thus giving players a very positive emotional experience.

5. Summary

The term NPC reveals their mission: they are mostly found in games with storylines, and as the objects of players' emotional projection, they are so important for games that want to tell a good story and improve players' emotional experience. Through the three perspectives of biology, physics and psychology, developers can create believable and better NPCs, meeting players' expectations; at the same time, we can also create complete characteristics and background of NPCs, allowing them to interact with players and scenes in game and witness the growth process of players. Finally, the behavior of NPCs also works as a way to strengthen players' emotional experience and establish relationships such as "protection", "cooperation" and "competition" in missions/tasks, creating diverse and deep emotional experiences for players.