Cards in Source of Thought are not independent units. Their neighboring works change their final combat values. Resonance is the system that turns a formation into a composition of ideas.
Only direct neighbors resonate
The current rule evaluates orthogonal adjacency—up, down, left, and right. Diagonal cards do not contribute. This makes relationships readable on a 5×5 board and avoids turning every local cluster into an opaque web.
Each adjacent pair compares its parameter profile. The absolute difference determines whether the relationship produces support or friction. Multiple neighbors are accumulated, then constrained by upper and lower clamps so one extreme grouping cannot break the battle.
Preview before combat
Resonance originally existed only inside the simulator. It now appears in Battle Prep as a modifier and final-value preview such as +15% or -10%. The player can move a card and immediately see the consequence.
Similarity is not decoration on the card. It changes what the card can do because of where it stands.
Position and resonance are separate
Grid bonuses represent exposure and role: front positions favor attack and hate, rear positions favor defense and lower hate, and lateral roles add additional variation. Resonance represents the relationship between works. Keeping the two calculations separate makes balancing and explanation possible.
Temporary similarity and future embeddings
The Unity-only MVP can estimate adjacency from the ten-parameter vectors in cards.csv. The architecture keeps that calculation behind a similarity provider so it can later use stored embeddings without rewriting battle logic.