Lotto Number

Lotto Number (ロットナンバー) is a system from the Mega Man Battle Network series introduced in Mega Man Battle Network 3. By inserting a number on the Number Trader inside Higsby's or AsterLand, Lan can obtain a reward, such as Battle Chips, Sub Chips, and Navi Customizer programs.

Mega Man Battle Network 3
The Number Trader becomes available alongside Higsby's after BeastMan's defeat. Many numbers are obtained randomly by buying nut-wafer chocolates in Yoka's Metroline station, each costing 500 Zenny. However, some of the numbers obtained (01928736, 09817262, 21237803, 23746172, 30902331, 31146320, 31912830, 42312003, 56098914, 63345398, 66720934, 72938474, 73984011, 81742195, and 91027364) give no rewards.

Mega Man Battle Network 4
The Number Trader appears inside Higsby's when Castillo becomes available.