Portuguese Solitaire is a single-deck, fully open patience on the Baker's Dozen board: thirteen piles of four cards, every one of them face up from the first move. It changes two things about Baker's Dozen, and both of them are about Kings. The Kings are not sunk to the bottom of their piles at the deal — a King dealt on top of a pile sits there, blocking everything under it — and an empty pile, which in Baker's Dozen is gone for good, here accepts a King and nothing else. No stock, no waste, no redeal. Free in your browser, no sign-up.
Goal: build all four foundations from Ace to King by suit.
The whole game turns on the Kings, so plan around them before anything else.
Portuguese Solitaire belongs to the small family of open games built on the Baker's Dozen deal, and the family is best understood by what each member does with spaces. In Baker's Dozen the Kings are buried at the deal and an empty pile can never be refilled. In Castles in Spain the build is by alternating colour and a space takes any card. Portuguese Solitaire sits between them: the Kings are left loose, so they can block, but a space will take one, so the block can be broken. It is listed in the PySol Fan Club collection, in Thomas Warfield's Pretty Good Solitaire lineage, and in Wikipedia's account of the Baker's Dozen variants, which describes it as "halfway between Baker's Dozen and Spanish Patience".
Played well it is one of the friendlier open games. Warfield's figures put the win rate near nine games in ten, and because everything is visible from the deal, a lost game is almost always a planning mistake rather than bad luck. The single-card rule is what keeps it honest: a long packed run is only as movable as its top card, so the order in which you dig matters far more than in games that carry sequences.
If you enjoy this shape, try Streets and Alleys for the same suit-blind build on eight piles, or Citadel, where cards that fit a foundation are banked during the deal itself.