Against passive players who rarely bluff, your strategy should focus on value betting more aggressively and calling less frequently. Since these opponents tend to check and call rather than bet or raise, you should bet more often with strong hands to extract maximum value. When they suddenly show aggression, especially with a big bet or raise, it's usually a sign of a strong hand, so folding marginal hands in such spots is often correct. Additionally, since they don’t bluff often, there's little reason to call down light—if they bet big, they likely have it. Lastly, exploit their passivity by stealing blinds and small pots more frequently, as they won’t defend as often.