Looking the questions of this site, it seems that D&D, in all its versions and variants, is by far the most played game. But that's not quite true of the people I know, so I think the proportions in Europe and USA may be different.
Are there any real statistics about the most played games? I'm specially interested in per-country or at least per-continent statistics.
Every quarter, Roll20 releases statistics on what systems are played on their platform. This is Q3 2021:
In percents: 53.7 D&D 5e, 19.8 uncategorized, 11.9 Call of Cthulhu, 11.5 all others, 3.2 Pathfinder, 1.4 Pathfinder 2e, .9 Warhammer, .9 World of Darkness, .8 D&D 3.5e, .6 Starfinder, .6 Tormenta.
This is helpful to compare similar systems, ones that require something like Roll20 to play. It's not so great at being comprehensive. In particular, what about the systems that don't require Roll20 to play? (For example, I play Dungeon World entirely in theater of the mind.) It also doesn't give you a further breakdown, but a virtual game might not be played in only one country anyway (mine aren't, not even the same continent).
I don't think there's a great deal of published, general information on this topic.
Among podcast listeners, there's an annual survey that includes what games listeners are playing. Informally, I would assume that RPG podcast listeners probably play a broader range of RPGs than the gaming population as a whole. Jennisodes has a discussion of the survey results.
