This system is the deck's main combo starter, and the cards which are often needed to get most, if not all of their plays started. Almost every, if not every deck has a primary system in it. Take for example the simplest form of decks to play; tour rabbit. Its main system is rescue rabbit with 2 sets of normal monsters in 3s in the deck, which, are meant to help you play the designated xyz monsters within the extra deck, that this deck wishes to play. If It works, then tour guide is then used to summon a lv 3 fiend, to xyz summon into sea serpent leviair, who then uses its effect to return rescue rabbit, to perform a 2nd xyz summon using the normal monsters. If the 1st rabbit xyz failed and rescue rabbit was destroyed and sent to the grave, tour guide would instead play sangan, and leave it there to let it get destroyed, to find the 2nd rescue rabbit in the deck, and try again. Notice that the main cards involved are rescue rabbit and tour guide; the normal monsters are only there to enable rescue rabbit to do its plays, and not much else. Lets take another deck, psychics. Their main system revolves around serene psychic witch, esper girl and overdrive teleporter. Serene psychic witch is 1st destroyed, and she banishes from the deck esper girl. When your turn comes around, esper girl is special summoned, and banishes a card. She is then tributed to play overdrive teleporter, and the banished card is added to your hand. Next, overdrive teleporter uses its effect, pays 2000 lifepoints and special summons hushed psychic cleric,and psychic commander. Cleric now discards a card and banishes esper girl again, and now, you synchro summon using hushed psychic cleric, and psychic commander, a lv 6 synchro monster. This time, as before, esper girl returns, and banishes a card. You then synchro summon a lv 8 monster using overdrive teleporter and esper girl, and add the next card to your hand. If you had grandsoil the elemental lord, you most likely discarded an earth monster with hushed psychic cleric, and now, you can attempt to summon him, as your grave now has 5 earth monsters; the earth monster discarded, psychic commander, hushed psychic cleric, esper girl and serene psychic witch. To identify a deck's main system, take a look at the deck, take a look at the plays it does, and think of the most ideal opening hand you can obtain with it. This hand, is more than likely its primary system

Now, going back to the enabler, the most ideal hand is likely its enabler. Not all the time that will be your opening hand. Like with rescue tour, you may not always draw rescue rabbit and tour guide; you may even draw the normal monsters long before you draw rescue rabbit. Same with the psychic deck in respect to using overdrive teleporter. What happens in that case? Does the deck simply lose as it cannot get to its main combo starter? For any good deck the answer is no. In addition to a primary system, some decks carry a second set of cards, not as important as the primary ones, but enough such that the deck can still function, or even use these set of cards to do its own set of plays outside of the main set of plays, or even find the enabling cards. These set of cards is called the secondary system; booster. Lets take a more specific version of rescue tour, dino rabbit. Its main system has already been identified, but with its system only being 4 cards, its not common for it to open perfectly. If it weren't for a secondary system, it'd be sitting there, relying on normal monsters and slower tactics to get through. As such, cards like pot of duality and jurrac guiba are added to the deck. With Jurrac Guiba, if it destroys a monster by battle, it can special summon another Jurrac monster with 1700 attack or less, most often itself. That in itself wont place targets for tour guide from the underworld to return by xyz 3 into leviair, but it achieves the purpose of rescue rabbit in playing the 1st xyz monster for the deck. Cards like spirit reaper and snowman eater also help fill the gap for tour guide, in that they can stall off attacks long enough to either let you draw into rescue rabbit, or even perform a rank 3 xyz summon. To identify the deck's booster system, Look at the deck, and think of the next set of cards you'd be happy to open with, excluding most cards from the ideal hand; this is your booster system. Ironically, the booster system is more important than the enabler system; If the enabler system goes haywire or the strategy collapses, One now has to decide what is he going to do. The strength of the booster system determines whether you continue dueling, using another strategy, or simply place your hand on your deck, and forfeit

Now one may ask, why is this important? It is simple. Every deck relies on a strategy, so its important to know what that strategy is when you design your deck. Your enabler system decides the strength of your deck; if its unstable, then your deck may very well be unstable. Your booster system helps determine how well you and your deck will do in the event things do not go as planned, which will come more often than not; remember, its a 2 man game. This is not only important for the deck wielder, but also who its against. In identifying a deck's enabler and booster system, one can identify the best way to disrupt a deck's strategy; remember that a deck's system determines its strength, and every system has a small flaw in them; exploiting this flaw will help one collapse the deck's strategy, and bring one closer to victory against it; This is part of the main concepts of the competitive side deck; A set of cards designated to disrupt the strategy of a particular deck. Its due to this that a good duelist takes time to learn off a deck, and learn off how it works, whether its to wield that deck as his own, or crush it where it stands

And there you have it, an explanation of how deck systems work, and how to distinguish them, hope its helpful