In Far Cry 4, explosive weapons and gadgets play a significant role in the gameplay experience, providing players with a range of options for combat and strategy. The following are the main types of explosives available in the game:

1. C4 Charges: These are powerful, remotely detonated explosives that Ajay Ghale, the protagonist, carries from the start of the game. Known for their lethality, a single C4 charge can obliterate enemies, vehicles, or obstacles, making them a versatile tool for various tactical scenarios.

2. Dynamite: Introduced in specific missions, dynamite functions similarly to a pipe bomb, reminiscent of the IEDs from Far Cry 2. It offers a throwable explosive option that can effectively tackle groups of enemies or destroy objectives.

3. Mines: The game includes motion-sensitive anti-tank mines that serve as a defensive mechanism. As enemies approach, these mines emit a loud beeping noise and flash a light, alerting players to their activation. Although Ajay starts the game with access to mines, they are not frequently encountered throughout the campaign.

4. M26 Hand Grenades: These standard hand-thrown grenades are commonly used by opponents in the game. Players begin with the ability to use hand grenades without the need for the cooking mechanic, which allows for immediate detonation upon throwing.

5. Grenade Launcher (M79): This weapon enables players to launch grenades from a distance, providing a way to deal area damage efficiently. The grenade launcher is particularly useful for creating chaos amid enemy groups.

6. Rocket Launcher (LK 1018): The most potent explosive weapon in Far Cry 4, the LK 1018 features homing capabilities, allowing it to target vehicles and enemies more accurately. Additionally, it can fire cluster bombs when equipped with the appropriate attachment, further enhancing its destructive potential.

In terms of signature weapons, Far Cry 4 does not feature any that are purely dedicated to explosives. Instead, signature weapons enhance more conventional firearms, such as SMGs, sniper rifles, and LMGs, focusing on improvements in damage, accuracy, or incorporating suppressors, which means players must rely on the standard explosive options listed above.

Overall, Far Cry 4 provides a diverse array of explosive gadgets and weapons, including C4, dynamite, mines, grenades, grenade launchers, and rocket launchers. However, there is a notable absence of signature explosive weapons, limiting specialized explosive enhancements in the game. This array of explosive options allows players to engage in exciting and varied tactical gameplay, utilizing the environment and their arsenal to overcome challenges in the game world.