Bonjour Phil, et merci.
No, there isn't a BLAM thread as such in the open forum, although there is a closed user group for people signed up to BLAM.
Several nationalities have their own 'Lead Adventure Club - X nationality' with private boards here on LAF, but as far as I know, there isn't a French one yet. So if you and any compatriots wanted to try to get a French Lead Adventure Meeting off the ground, please notify Prof Witchheimer and he is usually willing to set up a closed board for you to invite French LAFers, and to talk about the organisation of your event, which I suppose would be a FLAM (or possibly a flambee

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I guess the thing to do would be to post a thread in the general wargames discussion board to ask how many French people would be interested in such a venture. LAF weekends have proved very successful and enjoyable in a number of other countries. It's perfectly okay to post in French by the way. Although English is the usual language of the forum, there is no rule to say English has to be used, so if you wanted to attract the attention of French LAFers, a thread in French to assess interest and start the conversation off would be perfectly alright

Bon chances!