Dice Hate Me
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I think the rules say this, but the question came up and was debated yesterday.That is correct - only one intern per player per round.
Let's say in a three-player game, player one takes an intern, and players two and three both place their field researchers on country tokens. Then player one also places his field researcher on a country, and players two and three pass.
At this point, there are still two unclaimed interns, and player one hasn't passed yet. Player one isn't allowed to take another intern, correct? I assume we move into the "Blend/Research" phase at this point.