You should bring a tournament-legal Deck as described above, along with any tournament supplies you will need, such as paper and pen to track Life Points, dice or counters if you are using cards which require them, extra sleeves to replace any that become damaged, and so forth
Unlike playing cards, they are sold in a huge variety of types, each with different characteristics, such as attack strengths or abilities
These have effects which either support a specific sub-archetype (such as "Xtra HERO Cross Crusader" with "Destiny HERO" monsters) or ones that support the general shared playstyle of "HERO", such as "Xtra HERO Wonder Driver" recycling "Change", "Fusion" or "Polymerization" Spells and "Xtra HERO Infernal Devicer" searching a specific material(s) mentioned on a "HERO" Fusion Monster
In that time, the likes of Blue-Eyes White Dragon and Dark Magician Girl have become indelible parts of not just the Yu-Gi-Oh