Knowledge Diffusion

_{Discovery Mechanics · Design document §1.2}

Knowledge Diffusion (Catch-Up Mechanic)

When a breakthrough becomes widespread among civilisations, it passes from cutting-edge discovery to common knowledge. This prevents runaway leads and ensures historically inevitable technologies reach everyone eventually. It counts only the civilisations a civilisation has met, and only breakthroughs it could study (their prerequisites discovered).

After the Printing Press (MC06): when half or more of a civilisation's contacts hold a CORE or STANDARD breakthrough, it arrives free 10 turns later, idea and all. The free exchange of printed ideas makes common knowledge genuinely common.

After the Internet (CP04): the delay falls to 5 turns, and UNCOMMON breakthroughs arrive the same way.

Always: RARE and UNIQUE breakthroughs never diffuse. Seeing what a rival has, its units and buildings, reveals it (observational revelation, §1.4): diffusion's first stage, which grants nothing but the knowledge that a thing is possible.

Proposed, not yet decided or measured: the old design's roll bonuses, before the Printing Press and for UNCOMMON and RARE breakthroughs, become effects on ideas: when half a civilisation's contacts hold a breakthrough, its idea occurs to the civilisation, or comes back if it was lost, and the larger bonuses add a head start. Only the automatic arrivals above are in the simulator.