S-Tec are ranks obtained in "Yu-Gi-Oh! Forbidden Memories" for completing a duel in a specific way. There are two ways to obtain S-Tec ranks in the game. Both ways involve participating in long battles that involve little offensive action. While S-Tec battles can be tedious, they are necessary if you want to obtain some of the game's rarest magic and trap cards. You can S-Tec against any duelist in the game, and you may need to S-Tec against a duelist more than once to get their rare card.
Start a duel with any of the game's duelists.
Play one card at a time. Destroy your monster's monster and magic cards as you go, but do not take away their Life Points. When you have played all of the cards in your hand, attack your opponent's Life Points directly and defeat them.
Create a deck with a lot of magic cards and monster cards with high defence. Start a duel and focus on getting your opponent to play all of their cards while protecting your Life Points. Destroy all of your opponent's monster cards, but do not attack their Life Points. The object is to win the duel by getting your opponent to play all of their cards.