Spiderette

Spiderette is Spider on a single deck and a Klondike layout: seven piles in a staircase, build down by rank, move same-suit runs, and discard each completed King-to-Ace suit run.

Halving the deck sounds like it should make things easier and does the opposite. With only four cards of each rank in play, the chances that the card you need is the right suit drop sharply, so off-suit placements pile up faster and are harder to undo. Add the requirement to fill every gap before the stock deals and you get a game rated Difficult despite being a third the size of its parent.

Spider compressed into one deck: seven piles in a Klondike-style staircase, top card face up. Columns build down in rank with suit ignored, and only a same-suit run moves as a unit. Complete a King-to-Ace run in one suit and it is discarded automatically. When you stall, the stock deals one card onto each pile — and every gap has to be filled before that deal happens, so an empty column must be used or lost. There is no redeal.

The rule that gaps must be filled before dealing is Spider's constraint in a smaller frame: an empty column is only worth having if you can spend it before the next deal. Build in-suit wherever the choice exists, because with only one deck there are just four of each rank and an off-suit junction is much harder to unpick than in the two-deck game. The staircase deal means the leftmost columns clear quickly — use them for early space rather than starting work in the seven-card column. Rated Difficult, and the difficulty is the single deck rather than the rules.