Player’s mechanics in cooperative games can be contextualized based on their relationship to other players. The following is a non-exhaustive list of inter-player mechanical relationships.

ORTHOGONAL

Player’s mechanical relationships are sometimes independent and can be considered orthogonal if it does not require, influence, or impact other players. Due to the team nature of even loosely cooperative games few mechanical relationships can be said to be truly independent, but some games have employed this sort of relationship in specific set pieces like in some of Gears of War’s levels where players progress on independent tracks. The mobs, items, and intermediate goals on these tracks allow the player’s actions to be nominally unrelated to the other’s.

RELIANT

A reliant mechanical relationship is one where any given player’s ability is dependent on another player’s actions. An example of this is Ibb and Obb, a two player cooperative platformer. In many of these scenarios, each player, and thus the team’s progress is dependent on the other player’s specific actions. For one player to be permitted to act, the other must do something first.

Obstructive

Similar to reliant mechanical relationships, obstructive mechanical relationships tend to have an absolute nature to them, however, whereas a reliant relationship is about one player’s actions enabling actions, obstructive relationships prevent action. An example of this is Overcooked, where a player’s presence on a station physically blocks other players’ access to the same station or even simply past the station.

COMPLEMENTARY

Complementary relationships are often driven by roles and optimization; the capabilities of one maximizing the capabilities of the other. In the case of MMOs a Tank allowed a Damage Dealer (DD) to perform their role unimpeded. However, play style preferences can also foster naturally complementary relationships in more open formats as players can define non-mechanically social or tactical roles.

SYNERGISTIC

Synergistic relationships are an extension of complementary relationships, but are unique in that they enable new capabilities beyond the sum of their parts. Aspects of a relationship could be considered synergistic if skills, abilities, play styles, amplify the capabilities of one or more of the players. A Support class’ defensive buff would be synergistic with a Tank’s naturally high defensive abilities, or a Range character’s mob kiting allows a DD’s area of effect spell to land in scenarios where they could not otherwise.

MOSAIC

Mosaic relationships are ones where individual actions are ineffectual or incoherent without the actions of other players. These types of relationships are often found where players’ individual actions are expressed through intermediaries, such as a ship. In Sea of Thieves, turning the helm, lowering and raising the sail, letting go and weighing anchor, and firing cannons would do nothing outside the concert of all of the actions. In mosaic relationships, each player’s actions and contributions are subordinated to the combine action of the whole, and might otherwise be irrelevant without those of others.

COLLINEAR

Collinear relationships are found in scenarios where there are one-dimensional goal. In death matches, every teammate’s kill count goes towards the team’s total; in a relay race, each player’s lap time is summed to the team’s time; in linear action games, each mob that’s killed enables the team to progress that much further toward completion.

TRIBAL

In tribal relationships, a player’s contributions are often contextualized on a team impact scale like a mosaic relationship, but do not strictly depend on the actions of others. Also, tribal relationships can be thought of in terms of outcome like collinear relationships, but do not frame themselves around mono-axial definitions of progress or success. For example, in a survival game, the team requires food, water, and other material resources, and each player can contribute to the whole by contributing along single or multiple vectors.