Editing Plugin Groups


What Are Plugin Groups?

LOOT assigns each plugin to one plugin group, with plugins belonging to the default group by default. Each group has a name and a list of zero or more other groups it loads after. In this way, it’s possible to concisely load groups of plugins after other groups of plugins.

Group load order is transitive, i.e. given three groups A, B and C, if C loads after B and B loads after A, then plugins in group C will load after plugins in group A even if no plugins in group B are installed.

The Groups Editor

A group must be defined before plugins can belong to it, and defining and editing groups is done in the Groups Editor, which can be accessed through the main menu.

The groups editor consists of an interactive graph displaying all defined groups and their load after metadata, and a sidebar containing input for defining new groups and a list of plugins in the currently selected group.

  • Groups are displayed as circular nodes in the graph, labelled with their names.
    • Groups that load after no other groups are displayed in blue.
    • Groups that no other groups load after are displayed in green.
    • The default group is displayed in orange.
  • Load after metadata is displayed as lines (edges/vertices) between nodes, pointing from the earlier group to the later group.
  • Metadata defined in the masterlist is greyed out, while user-defined metadata is not.

If any group definitions reference another group that does not exist, the groups editor will create the missing group as user metadata. This is to help when there is user metadata that says the user-defined group B must load after the masterlist-defined group A, but then group A is removed in a masterlist update. In that case, just open up the groups editor and link group A back into the graph as it was before.

New load after metadata can be added by clicking on one group and dragging a line from the white circle that appears to another group.

Clicking on a group will cause any installed plugins in that group to be listed in the sidebar.

Right-clicking a load after metadata line will remove that load after metadata, and right-clicking a group will remove it. Masterlist metadata cannot be removed. A group cannot be removed if any installed plugins belong to it.

The graph can be zoomed in and out of using your mouse’s scroll wheel. Left-clicking and dragging an empty space will move the whole graph, while left-clicking and dragging a node will move it. Multiple nodes can also be selected by left-clicking with the Ctrl key held down, then dragging the box that appears over the nodes to select. The selected nodes can then be dragged around together.

Rules For Using Groups

The groups editor enforces a few rules:

  • A group cannot load after itself.
  • A group cannot load after another group if the other group does not exist.
  • It’s not possible to delete groups that are defined in the masterlist.
  • It’s not possible to remove ‘load after’ entries from a group if they were defined in the masterlist.

Another rule that the groups editor cannot enforce is that group metadata must not introduce cycles. A simple example of cyclic groups is where group B loads after group A, and group A loads after group B.

A more complex example involving other types of metadata is where

  • A.esp is in the early group
  • B.esp is in the mid group
  • C.esp is in the late group
  • A.esp has C.esp as a master
  • The late group loads after the mid group, which loads after the early group.

This will cause a cyclic interaction error when sorting, because the groups say that the load order should be

  1. A.esp
  2. B.esp
  3. C.esp

but A.esp must load after C.esp to satisfy its dependency.

Cycle Avoidance

Groups must not introduce cycles, but in practice this can be quite hard to ensure. LOOT helps by avoiding cycles that have an “obvious” solution.

  • If group membership contradicts where a plugin’s masters, master flag, load after or requirement metadata say that plugin should load relative to another plugin, the plugins’ groups’ relationship will not be enforced. For example, if:

    • dependent.esp belongs to group early
    • master.esp belongs to group late
    • master.esp is a master of dependent.esp
    • The late group loads after the early group.

    dependent.esp must load after master.esp due to the former being a master of the latter, but their groups suggest that master.esp must load after dependent.esp, so the group metadata is ignored for that pair of plugins.

  • In addition, if one of a pair of plugins with contradictory groups is the default group, that plugin will also have its group metadata ignored for all plugins in all groups that load between default and the other plugin’s group.

    For example, if:

    • A.esp is in the default group
    • B.esp is in the mid group
    • C.esp is in the late group
    • A.esp has C.esp as a master
    • The late group loads after the mid group, which loads after the default group.

    This will not cause a cycle, as:

    • A.esp’s group is ignored for C.esp as their groups contradict C.esp being a master of A.esp
    • A.esp’s group is ignored for B.esp as B.esp is in the mid group, which loads between default and late.

    The sorted load order is therefore:

    1. B.esp
    2. C.esp
    3. A.esp

    This is very similar to the example given in the previous section which did cause a cycle: the only difference is that the early group is now default.