`World#createExplosion()`'s implementation uses one of two explosion types (`World.a`, unmapped enum subtype), either `MOB` or `NONE`, depending on the `breakBlocks` boolean passed to the method. If `breakBlocks` is set to true but the `mobGriefing` gamerule is set to `false` in the world, the explosion will not break any blocks because the `MOB` ExplosionSource will check for that gamerule and use `Explosion.Effect.NONE` if it is false.

The `createExplosion()` method should only respect this gamerule if a `source` entity is passed to the method. If `null`, then it is expected that blocks will break in the world if `breakBlocks` is set to true. This behaviour should be better detailed in the Bukkit Javadocs and the implementation adjusted to match the expected behaviour.