I had a look at a copy of En Garde! recently (1975 edition), and the things that mainly struck me were:
- the rules were very poorly expressed. I read a lot of rules and technical documentation, and I think I’m pretty good at getting the gist of things, but this took work to understand.
- in addition, there’s quite a lot missing, like a list of things that should happen in a single week/month/turn. If I were to run it I’d need to make up quite a lot, and in effect write my own supplementary rulebook.
- as with early D&D (and to a large extent even late D&D), there’s basically nothing in the rules about characterisation.
While I look at it with modern eyes and think that in rules terms it falls under the broad definition of “boardgame” rather than “role-playing game”, when I think about my own early experiences with RPGs there’s probably about as much intrinsic role-playing here as there is in Basic D&D.
I’ve played a certain amount of Arkham Horror (2nd edition), and if you don’t do incidental role-playing (i.e. talk that isn’t supported by the mechanics) it can be a very joyless exercise in rolling dice and collecting clue tokens. I suspect En Garde! would be the same.