Pendulum Limit

Pendulum Limit (ペンデュラム・リミット) is the number of face-up Pendulum Monsters that can be Special Summoned from the Extra Deck to the Main Monster Zones during that turn, while a Pendulum Monster is already in the Extra Monster Zone, without the usage of Link Monster's Link Arrows. (either via a Pendulum Summon or another Special Summon.)

Rulings

 * If a Pendulum Monster is in the Extra Monster Zone, the player can Special Summon as many face-up Pendulum Monsters from the Extra Deck as they choose to their Main Monster Zones, as long as they stay within the Pendulum Limit. (Before the player can Pendulum Summon multiple face-up Pendulum Monsters from the Extra Deck, a Pendulum Monster must already be in an Extra Monster Zone.)
 * The player's initial/base Pendulum Limit is determined by the number of face-down cards in your Extra Deck.
 * 1-10: 5 Pendulum Monsters
 * 11-13: 4 Pendulum Monsters
 * 14-17: 3 Pendulum Monsters
 * 0, 18-20: 2 Pendulum Monsters
 * The following methods can be used to increase the player's Pendulum Limit.
 * Card effects can also increase (or decrease) a player's Pendulum Limit. This change is permanent unless another card effect alters the Pendulum Limit.
 * The initial/base Pendulum Limit is determined by the number of face-down cards in your Extra Deck (Look above.) For example, if you have 18 face-down cards in your Extra Deck and then Special Summon "Starving Venom Fusion Dragon," your Pendulum Limit becomes 3.
 * If a player starts the Duel with...
 * 0 face-down cards in the Extra Deck: They can only Pendulum Summon up to 2 face-up Pendulum Monsters from the Extra Deck, and their Pendulum Limit can only be increased by card effects.
 * Number of face-down cards in their Extra Deck (more than 0) and later depletes it: They can still Pendulum Summon up to a certain number of face-up Pendulum Monsters from their Extra Deck, depending on their Pendulum Limit before that.
 * Pendulum Limit's rulings do not apply if...
 * Link Pendulum Monsters; they must be Pendulum Summoned to either an Extra Monster Zone or a Main Monster Zone(s) that a Link Monster or Link Spell points to.
 * If a Link Pendulum Monster is in a Pendulum Zone(s) OR a Link Monster or Link Spell points to a Main Monster Zone.
 * The maximum Pendulum Limit for each player is 5.