Two decks of La Belle Lucie mean eight foundations and more spare cards in the stock, which is exactly what makes this fan game winnable: 50%.

Intelligence Solitaire is La Belle Lucie Solitaire played with two decks instead of one. Doubling the deck gives you eight foundations instead of four and more spare cards waiting in the stock, which is what actually makes the game winnable. Expect to win about 50% of the deals you play, which puts the difficulty at medium. Two decks are dealt, and skill matters more than luck in getting there.
Other fan-style games worth a look include La Belle Lucie, House on the Hill, and House in the Wood.
Where this one rewards patient fan-building, Spider Solitaire swaps that for long descending runs and a very different pace.
If you run into anything odd or have an idea that would make the game better, please contact me.
Enjoy!
8 foundation piles: Build up from Ace to King in the same suit.
18 fans: Build up or down by suit. Only one card moves at a time, between fans or onto a foundation. Each fan starts with three cards, dealt face-up. Any ace turned up during the deal goes straight to its foundation and is replaced by the next card from the stock.
Stock: Click the stock to deal one card to every fan. There are no redeals.
There are eight foundation piles.
A card can be added to a foundation pile if it's one rank higher than the pile's top card and of the same suit. So the only card that can go on an 8 of clubs is the 9 of clubs. A pile holds at most 13 cards.
The top card of a foundation pile can move back into play if another pile will take it, though an empty fan can only be refilled by the stock, never by hand.
18 fans of three cards each, all dealt face-up.
A card can be added to a fan if it's one rank higher or lower than the fan's top card and of the same suit. So the cards that can go on the 4 of spades are the 3 of spades or the 5 of spades.
Any card not covered by another can be played onto a foundation or another fan, as long as that fan isn't empty.
An empty fan can only be refilled by the stock's next deal, one card at a time. If the stock has run out, empty fans stay empty.
Only one card moves at a time; sequences can't be moved as a group.
The stock is made up of whatever cards are left after the deal.
Click it to deal one card to every fan. You can't pull a specific card from the stock by hand, and once it's empty there's no redeal.