Rules of Movement A Bishop can move from a square (file1,rank1)(file_1, rank_1)(file1β,rank1β) to another square (file2,rank2)(file_2, rank_2)(file2β,rank2β) only if the following condition is met: β£file1βfile2β£=β£rank1βrank2β£|file_1 - file_2| = |rank_1 - rank_2|β£file1ββfile2ββ£=β£rank1ββrank2ββ£ This means that a move is legal only if the absolute difference in file and rank is equal. Let's look at some examples. Examples a6 β f1 Start Position: a6 = (1,6)(1, 6)(1,6) Target Position: f1 = (6,1)(6, 1)(6,1) Calculation: File difference: β£1β6β£=5|1 - 6| = 5β£1β6β£=5 Rank difference: β£6β1β£=5|6 - 1| = 5β£6β1β£=5 Result: β Legal Move ( both differences are 5 and equal) c3 β e5 Start Position: c3 = (3,3)(3, 3)(3,3) Target Position: e5 = (5,5)(5, 5)(5,5) Calculation: File difference: β£3β5β£=2|3 - 5| = 2β£3β5β£=2 Rank difference: β£3β5β£=2|3 - 5| = 2β£3β5β£=2 Result: β Legal Move b2 β e4 (Invalid) Start Position: b2 = (2,2)(2, 2)(2,2) Target Position: e4 = (5,4)(5, 4)(5,4) Calculation: File difference: β£2β5β£=3|2 - 5| = 3β£2β5β£=3 Rank difference: β£2β4β£=2|2 - 4| = 2β£2β4β£=2 Result: β Illegal Move Other Special Notes Always stays on squares of the same color. Can control up to 13 squares from the center.
