Seams
Problems that live entirely at a boundary
Loop points, edit points, cut points, boundaries between two colours. Each of these is a place where an artefact hides, and each becomes tractable once you solve for the right quantity.
4 possibilities
The other axis
Verticals answer "what area is this in". Collections answer "what is it for". They are meant to overlap, and a possibility appearing in three of them is not a mistake.
Problems that live entirely at a boundary
Loop points, edit points, cut points, boundaries between two colours. Each of these is a place where an artefact hides, and each becomes tractable once you solve for the right quantity.
4 possibilities
Bounded rules that produce a recognisable family
Marks, sets and sounds generated from a rule set rather than drawn individually. The output varies; the identity does not. The hard part is always the bound.
5 possibilities
Simulation and geometry written as maths, not imported as a plugin
Approaches where the interesting part is the maths and the dependency budget is zero. Often cheaper, often smaller, occasionally the only thing that fits the constraint.
4 possibilities
Default solutions and the distinct alternatives to them
Most interface and game problems get solved the same way every time. Each entry here is a materially different way to answer a question you already know the default answer to.
6 possibilities