If there is no object or unit present at grid 1, the projectile magic or crossbow arrow will hit the next colored grid, i.e. grid 2, e.t.c.
This projectile guide does not take Step (elevation) into account. Generally if the unit is 3-Step below it is safe to be ignored.
Unlike Final Fantasy Tactics, fallen body counts as an obstacle, equally a standing unit.
Destructible objects such as grass, bucket and rock have lower height count and can be ignored in a horizontal trajectory.
Indestructible objects such as building and wall DO block the projectile if its trajectory even slightly touches the obstacle.