Open Fire is Chapter 14 of Fire Emblem: Thracia 776.
Subjective: The following part of this article is based upon the editor's personal experiences and opinions, and therefore may not be applicable for all readers.
This is the first defense chapter of the game and likely one of the hardest without using the right setup. The enemy will send several Armor Knights and a few Mages into the city after breaking the four cracked walls. They are not too powerful but will constantly be spawning from all sides, so you will have dozens to deal with. There are three bosses, although two can be ignored if you avoid engaging them.
If you have ignored supports up to this point, now is the time to start using them. Keeping the right units within three spaces of units they support will make this chapter much easier. The most effective method for clearing the chapter is to cluster your units in front of the castle leaving three to guard each choke point. Keeping them in close proximity allows you to use Nanna's charm ability, the King Sword's charm ability (granted to whomever has it equipped), and whatever other supports you have to maximize your avoid and minimize damage. Staying toward the center also allows you to avoid the ballista fire. Because of his supports with both Nanna and Leif stacked with Nanna's charm skill, Finn is an excellent choice for a defender. Brighton using his support with Machyua and Asvel using his support with Leif can be very potent as well. Bear in mind that the unit guarding the middle choke point will take the brunt of the attack, so make that one your strongest. By keeping your units close you can have Nanna and a King Sword holder support all three at the same time, with other supports closer to their specific defender. With the right setup, your chances of surviving the onslaught will be much higher.
However, even with this strategy the first boss can still be troublesome. He will start moving after a few turns and try to attack whichever unit is guarding the center. He has both a Horseslayer and a Master Lance, so be very wary of him once he starts moving. Also keep in mind that the Master Lance is a 1-2 range weapon, so a melee weapon won't be able to counterattack him. Guerrilla attacks with Dean can help weaken him for the kill. Also be aware that several Dragon Knights will appear from the south on turn 8. They will also attack if they get close, but they will only have one or two turns to do so unless you have started moving outward.
If you want to get everything out of this chapter, you will have to take a few risks. You can visit the southern houses to get two weapons exclusive to this chapter, recruit the only Bard in the game, Homer, and visit at least three red houses within the city so that you will go to the next gaiden chapter. Visiting the three houses is very easy if you take advantage of the first two turns before the army arrives. Each visited house will cause another civilian to appear in the gaiden chapter, so try to stop by all of them if you can as each civilian gets you another Stamina Drink. Recruiting Homer requires that you move Nanna to the red house next to the arena in the upper right part of the city. This will most likely result in Nanna having to take a shot from the ballista, but she should survive even if she is hit. Again, it is best to do this within the first two turns.
Getting to the houses is the most difficult. Sending Eda out early in the chapter while avoiding the ballistae and enemies will allow her to get to the house in the right corner safely, but be very careful of the Dragon Knights that will show up in that area. Getting to the lower left house will involve quite a bit of risk taking and luck, but this can be mostly bypassed by using a Warp Staff. On the final turn, warp Dean to the house, have him visit it, then have him fly to the left so that he is out of the boss' range but not in the ballista's. Ideally he will survive the turn and you will still get your Dragon Lance. Otherwise, your only option to get the Lance is to clear out enough of the army to send a group outside of the city, get through the ballista fire (note that it has 15 range and is stronger than regular ballistae), and fight Paulus. He is easily the strongest enemy on the map, so be very careful if you make it this far.
- Uniquely both Dean and Eda are considered to be in the different army for this chapter, compared to the rest of player's units. Gameplay-wise that means they will not recieve Leadership bonus from any other unit present on the battlefield.