A brand new type of TM introduced in Pokemon Sword & Shield are known as TRs. TRs are Technical Records that allow trainers to teach their Pokemon certain Attacks that they normally can't learn by Leveling Up. TRs are basically what TMs used to be back in the first number of Generation of Pokemon, since they have limits and will Break after just one use. Usually, TRs are the best known Pokemon Attacks players can teach their Pokemon. In total, there are a hundred different TRs to be found and obtained in Pokemon Sword & Shield.
Unlike TMs, however, TRs can only be obtained from Max Raid Battles, usually being the same Type of Attacks as the Typing of the Raid Boss Pokemon. For example, you will receive Fighting Type TRs by defeating a Fighting Type Raid Boss. TRs can also be purchased from staff members in the Wild Area.
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