player must avoid enemies while proceeding through a level, as well as racing elements. Although the games can be beaten with a minimal amount of exploration and side quests, the player is frequently rewarded for solving puzzles or exploring hidden areas with helpful items or increased abilities. Some items are consistent and appear many times throughout the series, such as bombs, which can be used both as weapons and to open blocked or hidden doorways, boomerangs, which can kill or paralyze enemies, keys for locked doors, magic swords, shields, and bows and arrows, while others are unique to a single game. Though the games contain many role-playing elements (Zelda II was also the only one to include an experience system), they emphasise straightforward hack and slash-style combat over the strategic, turn-based or active time combat of games like Final Fantasy. The game's role-playing elements, however, have led to much debate over whether or not the Zelda games should be classified as action role-playing games, a genre on which the series had a strong influence.