The Smart Bomb (スマートボム, Sumāto Bomu) is an item in Super Smash Bros. Brawl. It is one of the most powerful thrown items in the game. Once it hits an opponent, travels a certain distance, or gets attacked, it produces a large, slow explosion that envelops a big range and damages everyone inside in increments of 1% for about three seconds with a total damage of about 30%. Characters caught in the blast can shift their position using Smash DI, but usually cannot escape until the explosion ends and flings them away. (Escape is possible with Smash DI as seen here.) The bomb does a great deal of damage but generally has the knockback to KO only at very high percentages.
There is a small chance that a Smart Bomb fails to explode; instead of going off it makes a distinctive echoing noise and travels through its target, causing flinching but no knockback. A dud Smart Bomb will still explode when attacked and may explode at a random time, even when picked up again. It will not explode by itself, however, if a player is holding it, although it may detonate almost immediately if that player throws it.
A bomb that explodes and causes damage to all characters within its range when thrown or attacked. The explosion from this device is so large, the deployer may be caught in the blast if he or she is not careful. In Star Fox, this item will explode after a set time or can be set off immediately with a button press.
The Smart Bomb comes from the Star Fox series. It was originally named the Nova Bomb. In Star Fox 64, it could either be locked on to opponents or triggered to explode after launch by pressing the button a second time. It also would explode on impact, or after it traveled a certain distance. It did not hurt Fox or his wingmen.