See also: Bomb Flower
Bombs are some of the oldest and most useful items in the Legend of Zelda series. They have appeared in every canon game except for Adventure of Link.
The Legend of ZeldaEdit
The first appearance of bombs was in The Legend of Zelda. They were useful items which could deal more damage than Link's wooden sword. They could be used from the beginning of the game, provided that Link found some.
A Link to the PastEdit
Bombs returned in A Link to the Past. They were now capable of destroying cracked walls, as well. This trait has remained throughout the series. Other uses include eliminating Stalfos, which could only be killed by knocking them down and then bombing them.
Bombs returned again and were still able to open cracked walls. The main change in bombs in Link's Awakening is that they would not explode until they were thrown and they could not harm Link. These traits would not remain, however.
Ocarina of TimeEdit
Bombs transitioned to 3D along with Ocarina of Time. However, Link now had to find a Bomb Bag before he could use bombs. This was unlike the previous games, where they could be used as soon as they were acquired. Bombs once again would open cracked walls and harm enemies. In this game, they were once again to harm Link and would explode in Link's hands if he was careless. This game also introduced the Bomb Flower, a bomblike-plant which could be used like a bomb once picked.