I'm not sure if this (or similar) has been suggested before, so apologies if I am going over old ground with this suggestion:
Currently the passive tree is a cornerstone feature of POE and customising builds. It adds great depth and keeps player coming back with new, exciting ideas. However, it is filled with some "holes", or dead zones, that many builds just don't go near. Whilst the community waits anxiously for each major release to see how the tree might change... overhauling the tree (and the roadways) can be a major time sink and balance risk for POE.
As an alternative I propose the following:
PASSIVE TREE POWER CLUSTERS
- a "cluster" of passive nodes are those nodes grouped in a larger circle (that groups the nodes in to similar passive attributes... sometimes called a "suburb").
- if a build uses ALL of the nodes within a "cluster" a stronger passive "cluster" bonus is granted.
- builds can then choose to build towards these lucrative cluster bonuses or forego them in order to travel wider throughout the tree.
Here are a couple of examples:
- GGG could change these cluster bonuses more easily without re-working the passive tree, which could drastically change the way builds could be made.
- GGG could make the cluster bonuses "theme based" depending on the 4 Month Leauges, such as Sacrifice of the Vaal... bonuses could be Vaal related.
- Cluster bonuses could be vary depending on the game mode: PvE or PvP.
<EDIT> - optional... if the bonuses do change between 4ML, GGG could decide whether to make the bonuses public or to keep the hidden for player discovery.
IMO there the above extends the Passive Tree into more greater areas for theory crafting without re-working the entire tree. Once built in changing the bonuses should be rather simply with the only considerations being balance related.
Anyway, that's the idea, hopefully it is of use.