From SmashWiki, the Super Smash Bros. wiki
Battlefield (戦場 Senjō) is a Super Smash Bros. Brawl stage that was first confirmed at E3 in 2006. It was also the first stage confirmed for Brawl. Its layout is very similar to that of its Melee counterpart - it consists of a central hard platform with ledges that may be hung from, and three stationary soft platforms that float above the hard platform. The stage elements are larger than those of Melee's Battlefield, and the blast lines that surround them are situated further away. The slopes on the stage's underside, beneath the ledges, can be "hugged", allowing many characters to more easily and more flexibly recover from offstage.
The visual design of Brawl's Battlefield involves recognisable and natural elements such as foliage, stone structures, and a landscape background, while Melee's Battlefield is plainer and has an abstract background. The stage cycles through different times of day, each with its own distinct background visuals and light. Unlike Smashville, the cycle does not reflect the actual time of day in reference to real time. It instead begins in its morning state, then progresses through daytime, evening, night and dawn phases, and returns to original morning state after four minutes. The stage's central platform features a sundial with a shadow that changes with the stage's time of day.
 In competitive play