Hey
tetramorph, firstly (my opinion ain't worth Diddley, but none the less...) you have my admiration your ongoing enthusiasm, and I applaud your effort to keep the original game vibrant. Well done!
I too have tried, on several past occasions, to pull together face-to-face groups from public notices. I too have failed, on several of those occasions, to get a group dynamic that "worked". None of my "random groups" have lasted longer than about a month, so I agree with you that it can be a tough ask.
In some respects it is simply the luck of the draw; there are a lot of folks out there with busy lives, or differing expectations, or limited ability/energy to be a genuine contributor, or whatever else. You can try to "screen" potential players, but ultimately you don't really know how a group will go together until you start playing. Convention play can be a similar gamble, except at a con you are guaranteed a game (or three in a row!) and can expect to get a higher ratio of enthusiasts. In terms of cons, I've found a number of small things that seem to "work" for introducing potential newbies to (in your words) "an old school game", so perhaps the same might be used for more general public groups?
If the idea is to immediately message players that
this is something different to what they're used to, then perhaps:
Set the player up with "disposable" pre-gens. No player effort, no player investment. Give them nothing but a character name, class, and maybe an in-game appearance/motivation in one or two lines. Let them see that you have a deck of pre-gens ready to go; maybe let them "pick a card" or take the top one off the deck.
Don't give them any game stats. This can save heaps of table time for the ref, and can help the players to click that "this" particular pre-gen is just one from a herd. If they don't like what they get, let the players swap, or draw another card.
I've also found it really works to give each player (i.e., each pre-gen) a simple,
personal objective to work toward. Stuff like: recover your Father's sword, pass through to a temple/village/person on the other side of the dungeon, get 300 gp to pay off family debt, find/rescue the butcher's son, gain advise from/petition a specific Holy man/Wizard/retiredHero, etc. etc. I've also found that
specific objectives work better than general ones. I.e., make it about the
dwarf gold or the
pirate gold rather than just "the gold" and see what a difference it can make to a fledgling campaign. All this will hopefully help the players to "play better"; you'll readily spot the players who are in/capable of "switching roles" after their first PC dies, and this alone can be fascinating and educational for the referee to observe. In my own experience of this technique, the more imaginative players tend to shine in this regard.
When they happen, try to make player deaths significant. Where practical, allow the player to utter some "famous last words". Continue to refer to the deceased character occasionally. This can be easy if others have looted his gear; have them write down on their sheet "Bungo's ax" or "Yemmit's spell book", or whatever. Also, as the ref, you might choose to remind the lawful-types (especially) that a deceased fellow's possessions should go to his family, temple, guild, or whatever... if the players buy into it, this can create interesting sub-plots and spawn a whole different branch of the game.
More immediately, perhaps, some simple props can hep to stimulate player interest. E.g., for M-Us I printed out out 1st level spells as one-liners in a little booklet like this:
www.fimp.net/makeabook.html. Piles of coins (plastic Pirate gold/silver can be had cheap at various thrift stores) for treasure can spark interest--particularly when getting certain treasure is a personal objective for the players. If you have them, miniatures can be a great prop--especially if the players have an entourage. It helps to show how large and cumbersome the player party can be, even if you do nothing with it other than show a marching order that will fit into a 5ft or 10ft wide passage. It should be apparently that the entire company of 15 Men, elves, and dwarfs cannot all be "at the front", nor operating effectively in a 20x30ft room.
This part I haven't tried yet, but is the result of my own thinking on a similar problem:
Have a plan for how you'll handle a TPK before it happens, so that if/when it does happen it doesn't feel like an abrupt end of play. I.e., have the players name an heir before they set off. Write that name down, or even have each player pull a pre-gen for their heir
before they set off. Have a cleric's temple or other player's guild somehow invested/engaged in at least one of the player objectives. Then, when the dungeon group takes a rest, reaches an impasse, or otherwise does anything that takes up game-time, cut over to a short scene back in town, or at their local camp. Has anyone noticed the players have gone? Are overdue? Is anyone calling for a search and rescue? Is there any reason to test the loyalty of hirelings left back at camp? This can help keep the players warm to the idea that the game is bigger than just these current PCs, and that "stuff" is still happening elsewhere in the world while they are down in the pits. In the event of a TPK, you can cut back to pursue these events, and the game can (we hope!) continue...
I hope that might help some,
tetramorph. Let us know how you go