Pairs starts with nine visible columns of five cards. Remove equal-rank pairs until all 104 cards are gone, including the 59 cards waiting in the stock.
A stock deal fills only eligible columns
Drag one exposed card onto another of the same rank, ignoring suit and color. Both disappear. Unmatched cards cannot be moved or built into sequences. Clicking the stock adds one card to each column currently holding fewer than five; full columns receive nothing.
Match before adding another layer
A new card can cover a partner that was already available. Check every exposed rank before dealing, especially when several copies let you choose which columns to open. Favor a pair that reveals complementary ranks beneath it. There is no stock redeal, and an empty tableau alone does not win while stock cards remain.