Low Level Deck

A Low Level Deck is one that only involves low level monsters (4 or lower, though level 3 is optimal for this design), and usually focuses on some of the more powerful effects rather than actually attacking to overwhelm your opponent. Closely related is the Low ATK Deck which is essentially the same, but can also include higher level monsters that have low attack, usually under 1000, though less than 1500 can also be considered low. Both use a similar strategy of getting otherwise weak monsters, usually Flip Effect monsters, on the field and activating their effects in order to clear your opponent's field of monsters and then attack directly.

King Tiger Wanghu poses a significant threat to this type of decks. This is because its effect destroys all Normal Summoned or Special Summoned monsters with 1400 ATK or below.

There is a variant of this that uses Normal Monsters with support cards that only target Normal Monsters. This includes the Ojama monsters and their various support cards.

Useful Low Level/ATK Cards

Monsters

• Relinquished, of course, can be the single most important card in a low level deck, as its ability takes away one of your opponent's monsters, prevents it from being destroyed, AND deals damage to your opponent if they attack while a monster is equipped to Relinquished. In Traditional Format, its Fusion, Thousand-Eyes Restrict, is even better since it prevents enemy monsters from attacking.
• (In Traditional Format) Sangan or Witch of the Black Forest for searching your deck for other low attack cards.
• Chaos Necromancer will most likely get a very high attack boost late in the game, as most of the player's monsters will get destroyed.
• Muka Muka and Infinite Cards is a nearly indispensable combo.
• Two Ultimate Baseball Kids and any other Fire Attribute monsters to increase their attack by 1000 ATK for each Fire monster on the field. DNA Transplant can be used to augment this further. This works especially well with a powered-up Raging Flame Sprite.
• Raging Flame Sprite is a powerful card to use, especially with Swords of Revealing Light and Axe of Despair or Mage Power equiped to it.
• Armed Ninja and Crimson Ninja can be used to destroy face-down Spells and Traps, respectively. For marginally higher ATK/DEF, replace Crimson Ninja with Trap Master.
• Copycat can imitate much high level monsters if played correctly, potentially making it one of the most powerful options in this kind of deck.
• Jinzo #7 and other cards that can attack your opponent directly.
• Junk Synchron can use it's effect to Special Summon a level 2 or lower monster from your graveyard and then you can use those 2 monsters to Synchro Summon Junk Warrior.
• Guardian Sphinx, while being a 5 star monster this card along with Level Limit - Area B can cause a number on your opponent while also being extremely useful for its high defense. Every turn just flip summon Guardian Sphinx to send all of your opponents monsters back to his/her hand.
• The Calculator can be useful although it relies on levels to boost its attack, early on if you are able to swarm the field its ATK can quickly be raised to do a lot of damage.

Spells

• Swords of Revealing Light, above any other type of deck, is almost a requirement to make this work.
• United We Stand, Mage Power, and Axe of Despair are powerful equips that can make a low level monster more capable of fending for itself. Megamorph can work very well in conjuncture with these.
• Level Limit - Area B, Messenger of Peace, and other stalling cards.
• Flint or Ekibyo Drakmord can be extremely helpful at preventing your opponent from destroying your monsters.
• Heart of Clear Water is extremely good for cards that deal damage over time like Ebon Magician Curran

Traps

• Gravity Bind can be used for an effect similar to Limit Level - Area B.
• Reinforcements and Castle Walls are good for preventing monsters from being destroyed, if they are high enough of a level.
• Magic Cylinder, Mirror Force, and similar cards can be used for redirecting damage back at your opponent.
• Sakuretsu Armor can help open up your opponent's line of defenses for an attack, and is especially good at getting rid of very powerful monsters.
• Gift Card can keep your Megamorph from cutting your monster's ATK in half, as well as ensure Raging Flame Sprite enough ATK to finish of your opponent quickly.
• Forced Back and Compulsory Evacuation Device can keep high level monsters from being summoned to your opponent's side of the field.
• Ordeal of a Traveler is useful for any monster, especially synchro and tribute summoned monsters, and can slow your opponent quite a bit as well as open up your opponent's line of defenses
• Even the All-Powerful Exodia the Forbidden One is made up of cards with levels 3 and lower. And the most powerful one is only 1000 ATK and DEF!
• The cards Bad Reaction to Simochi and Rain of Mercy can be used in good combination to effectivly raise your life points while lowering your opponents.

Extra Deck Cards

• Junk Warrior is great in a low level deck (even though it isn't a low level monster) because when this card is Synchro Summoned, it gains ATK equal to the total ATK of all Level 2 and lower monsters you control.

Low ATK Only

You can also include a few other comboes if you go with low ATK only, as many high level cards with incredible effects exist that have less than 1000 ATK.

• Winged Kuriboh, Transcendent Wings and Winged Kuriboh LV10 can devestate an opponent later in the game, as they will most likely have high-level monsters since most of your monsters will be used as shields.
• Nobleman-Eater Bug and Hade-Hane for destroying monsters on the field or returning them to their owner's hand.
• A combination of Destiny Hero - Defender and Dreamsprite can prevent an opponent from attacking, as D. Hero Defender has a DEF of 2700, higher than the ATK of many high level monsters.
• Skull-Mark Ladybug can be helpful, as its effect can be activated in response to battle or card effects that destroy it.
• Since Hayabusa Knight and Mataza the Zapper can attack twice in a turn, powering them up with Equip cards can make them some of the most versatile cards available.
• Millennium Shield, Labyrinth Wall, Guardian Sphinx both make good shields with high DEF and no ATK.
• Aitsu, Koitsu, Soitsu, and Doitsu can make a great combo as well. By sending Koitsu or Doitsu to the Graveyard and using Call of the Haunted or Premature Burial to bring them back to the field, they can then be equiped to Aitsu or Soitsu, which destroys the cards used to summon them without destroying the monsters, as they are now considered Spell Cards. Additionally, having both Union Monsters equipped gives you two monsters, one with 3000 and another with 2500 ATK, equivalent to a Blue-Eyes White Dragon and a Dark Magician!
• Add Defense Draw because if your monsters that have very low ATK and can cause big damage to you in battle, you would take no damage at all.

Notes

For decks with many low-level Normal Monsters, other helpful cards would include Sword of the Soul-Eater, The League of Uniform Nomenclature and Dark Factory of Mass Production.