Battleground Effects, sometimes referred to as BGE or BGEs, is a term we use to describe the special rules for any battle in the game.
GLOBAL BGE
A Global Battleground effect provides a boost to all cards of a specific Trait. Global BGEs are announced the week before it begins and each BGE will run for three weeks.
A BGE boost can be anywhere from making one Skill stronger, to boosting the Health of any card with that specific Trait.
For example:
The Grand Opera BGE began on January 31, 2019 and ended on March 14, 2019. During that time, this was the effect:
All Musical cards gain 30% of their base Attack when they deal damage attacking, and are Shielded for 20% of their base Health every turn.
Global BGEs, for the most part, are global: they affect nearly every area of the game.
Looking for upcoming event information? Check out the Upcoming Special Events Forum Thread, updated regularly.
SPECIAL EVENT BGE
There are also special BGEs. Special BGEs usually apply to specific areas of the game (for example, the AT League or Clash Events.
If you're ever unsure, check your in-game special events button on the main menu, the information button (i) in special events, or tap the icons at the top center of any Battle.
If you have any questions, let us know.