Face it, if someone's a good target for assassination, they almost certainly know it. They'll expect their food to be poisoned. So instead, poison the cutlery, or the glass. That way, when they eat the proven-safe food (or pretend to eat the food they can't risk testing), they'll get the poison that way.
- A Game at Dinner, a recurring In-Game Novel in the Elder Scrolls series, tells of a paranoid prince who poisons suspected spies this way, and offers them an antidote — the idea, of course, being that by taking the antidote, they'll be admitting to their treason. He lied, though. Not being certain who was his enemy, and not wanting to poison someone loyal and lose his Magnificent Bastard status, he poisoned only the so-called "antidote".
Hello, Unknown Troper. You'll need to get known to lend a hand here.