Each site adopts a random neighbor's opinion — exact interface dynamics, consensus time, and coarsening domains
Rule: Pick random site i; pick random neighbor j; set sᵢ = sⱼ
Conservation: ⟨magnetization⟩ = const; it's a martingale → consensus prob = ρ₀
Consensus time: T_c ~ N² (2D), T_c ~ N² ln N (2D square) — slow coarsening
Interface density: ρ_I(t) ~ 1/ln(t) in 2D — logarithmically slow coarsening