Is the 'include random transaction' rule a strict Nash equilibrium in Kaspa?

No — the 'include random transaction' rule is a weak Nash equilibrium in Kaspa but not a strict one. A weak Nash equilibrium means no single miner can do strictly better by deviating alone, but a strict equilibrium would require that any deviation makes things worse; the weaker version leaves room for miners to be indifferent. Researchers note this limitation is not unique to Kaspa: it applies to all 'Inclusive' protocols — any algorithm that allows parallel blocks to coexist, which covers all DAG-based protocols. For a beginner, this matters because it signals an open area of research into miner incentives, not a flaw specific to Kaspa.