Pendulum Scale

A Pendulum Scale (Japanese: ペンデュラムスケール Pendyuramu Sukēru, abbreviated スケール in card text) is a set of indicators unique to Pendulum Monsters. Two of them are located above the "Monster Effect" text box of the Pendulum Monster, with the "Pendulum Effect" of the Pendulum Monster placed between them. All Pendulum Monsters have two Pendulum Scale values, signified by the blue symbol and the red symbol.

Pendulum Scales are used in Pendulum Summoning. If there is a Pendulum Monster in both of the two Pendulum Zones, once per turn monsters in the hand and/or Pendulum Monsters that have been sent face-up to the Extra Deck can be Pendulum Summoned as long as their Levels are in between the Pendulum Scales of the two monsters. (Therefore, monsters cannot be Pendulum Summoned if the monsters in the two Pendulum Zones have the same Scale, or Scales that are only one number apart.) As there is currently no monster with a Pendulum Scale of 0, it is currently impossible to Pendulum Summon Level 1 monsters. In the anime, the Pendulum Scale appears as a glowing number below the Pendulum Monster when it is in the Pendulum Zone.

All Pendulum Monsters seen to date have the same Pendulum Scale value on both sides of their card. It is currently unknown whether a monster can have two different Pendulum Scale values.

A monster's Pendulum Scale seems to have some link to its Level, with higher-Level monsters being more likely to have lower Scales, with some exceptions.

As with Levels, Ranks, ATK, and DEF, there appear to be some unofficial conventions that govern how high or low a monster's Pendulum Scale values may be. A monster's Pendulum Scales may be as low as 2 or as high as 7 in normal cases; having a Scale of 1 or lower or a Scale of 8 or higher requires that the monster's Pendulum Effect have negative effects or conditions that restrict its use. More recently, Pendulum Monsters with Scales of 1 and 8 have been seen without any constraints.

As with all four of the above, a monster's Pendulum Scale may change from its printed number during a Duel due to other card effects. Currently in the OCG/TCG, a monster's original Pendulum Scale may range from 1 to 10; no effects can currently reduce a Pendulum Scale to below 1, but effects can theoretically raise the Pendulum Scale to any number above 10 (e.g. "Yosenju Shinchu R", "Performapal Guitartle"). In the anime, original Scales of 11 and 12 have been seen.