Generally, monsters with 4 stars and below are normally summoned, unless otherwise specified; only monsters with 4 stars or above require sacrifices, unless otherwise specified. The rules for summoning sacrifices are as follows: Monsters with 4-6 stars must be summoned normally. One monster is used as a sacrifice; those with 7 stars and above use 2 sacrifices; divine cards and some forbidden cards require 3 sacrifices; some cards require specific conditions, 1) If a designated monster is used, it can be specially summoned directly , like the true ●Red-eyed Black Dragon, you can use the Black Dragon Hatchling to special summon it from your hand. LV monsters such as the Armed Dragon LV3 can be directly upgraded in the ready state (Special Summon an Armed Dragon LV5 to play); 2) Use any hand to send a special summon to the field, Such as a certain demon of the angel tribe; 3) Summoning by using all the monsters on the field as sacrifices, called? I forgot what it came from; 4) Use monsters of the same race (specified number), such as the three Harpy sisters, the Disruption King, and some alliance monsters. . . That's basically it, haha. . .