My brother's girlfriend noticed that some Dominion expansions have a recommended age of 13+, while others have 14+. Does anybody have any idea why?
Originally they were all 8+, in 2006.
Mattel managed to have toys made in Chain with lead paint, in 2007. A bipartisan effort ensured that kids would never have to fear that their books or card games or other products that had never had lead ever would somehow have lead; if you want to say younger than 13+, they all need lead testing, on each print run. This is prohibitively costly (unless you get your lead testing done in... China, like Mattel does). So, Dominion switched to saying 13+.
One printer (ELM) felt that actually the requirement was 14+. That was their reading of whatever. So the copies made by them say 14+, and other copies say 13+. We don't use them anymore for some reason, so eventually they will all say 13+.