A handicap gives one team an imaginary head start. "Lecce +1.5": add 1.5 goals to Lecce before you look at the score.

Milan 2–0 Lecce → with +1.5 it reads 2–1.5, Lecce still "lose" → bet lost. Milan 1–0 → 1–1.5, Lecce "win" → bet won. So Lecce +1.5 wins on a draw, a Lecce win, or a one-goal defeat.

Negative handicap the other way: "Milan -1.5" needs Milan to win by 2 or more. Half-goal lines (.5) never tie.