power-ups. In series such as the Castlevania and Ninja Gaiden games this object is a candle or lantern, while in the Mario franchise, the oft-used container is the "question block". In the Sonic series, the power-ups in the 2D titles are usually found in cubic static TVs (named "monitors"), while in 3D games they are enclosed in capsule-like boxes. In beat 'em up games, level-themed objects such as crates, barrels, or mailboxes serve as containers. In many games, such as the Mega Man series, power-ups can be obtained through the elimination of enemies. In some games, power-ups may be left within plain view, such as in R.C. Pro-Am. It is also typical for games to require the player to travel a certain way or perform a specific action in order to attain said power-up, such as bombing through specific blocks in Super Metroid. Power-ups can also be obtained by interacting with certain objects at specific points in the level, e.g. the tractor-trailer truck in Spy Hunter. Treasure chests In many video games, especially role-playing video games, treasure chests contain various items, currency, and sometimes monsters. For certain role playing games, some chests are actually mimics, in which a monster looks like a chest, but will attack the player when they attempt to open it. This is notably seen in the Seiken Densetsu and Dragon Quest series. Treasure chests provide a means for the player to obtain items without paying for them in stores. In some cases, these chests contain items that cannot be purchased at stores. Chests may be locked, requiring a key of some sort. For certain games, keys can only be used once, and the key is destroyed during its use. For other games, having a particular type of key means that the player can open any of the chests with a matching lock. For most games, once a chest has been opened, the contents remain empty, although they may be repopulated with possibly different items during different stages of the game. This is different from perishable containers, such as crates and jars, which tend to reappear if the player exits the area and then returns. Selection bar Instead of having players collect a power-up that is instantly activated, the players may be allowed to select which power-ups they want to use. This is commonly implemented through a 'selection bar' which contains a number of power-up effects. To