Brenner



The Brenner line is a special high-level PvP event that is periodically open. It was last available September 20 through October 11, 2021. In this event, players fight battles in which they try to destroy each other's bunker. To access it, click on the Brenner watchtower in the far east part of your world map. (You can also visit the watchtower even when the event is not active, but you can't do anything other than upgrade your base.) The event is open to any players level 20 or above. However, because of the nature of the event, it is very difficult for lower-level players to have a chance. The full announcement of the event details can be found in this Facebook post.

The battles are like normal PvP battles, but with the following exceptions:
 * The lineup has been expanded. You may take a total of 1 hero, 5 infantry, 4 stormtroopers, 3 heavy infantry, 3 specials, 2 vehicles, 3 heavy machinery, and 3 supports, as well as 1 clan squad and 1 clan support. You must take at least 16 units in order to battle. A battle costs 100 fuel.
 * Each side has a bunker which supports your side by firing its cannon. The objective is to destroy your enemy's bunker; this is the only way to win.
 * Winning a battle earns you a Brenner chest, which is much larger than a regular chest, as well as some Brenner Emblems of Heroism.
 * The chest drop rate is Legendary (2%), Elite (5%), Special (10%), Rare (25%), Ordinary otherwise.



You earn various items from the battles which can be used either in the event shop, or to upgrade your bunker. These are:
 * Brenner Emblem of Heroism (silver) -- earned from winning battles in the event (75% for 5)
 * Brenner's Emblem of Valor (gold) -- have a chance to appear in bunker chests or from winning battles (25% for 1)
 * Brenner's mark of Excellence (gold) -- gained from the overall ranking (1 mark per Brenner victory)

Note that the emblems stay in your inventory after the event, so you can save them for the next round or use them to upgrade your bunker even when the event is not active. However, the marks are reset each time, so you have to start from 0.

Upgrading your bunker works like upgrading anything else, except that it requires Emblems of Heroism in addition to the regular costs. Furthermore, your bunker gains additional powers once it has been leveled up: These can be used every 30 seconds.
 * level 2: artillery bombardment
 * level 3: healing
 * level 5: discharge
 * level 8: personal shields

The October 2020 update added another ability, the Garrison, which appears at level 7. This allows you to select a special unit which is automatically deployed in front of your bunker after 30 seconds have elapsed in the battle. At the moment, only one garrison unit, the bunker machine gun, is available.

Event resources
There are a few different resources that can be obtained during the course of the event. Emblems of Heroism are earned as a reward from winning battles and from bunker chests. Winning a battle has a 75% chance to reward 5x. 10x of them can be converted to 1x in the event shop.

Emblems of Valor are earned as a reward from winning battles and from bunker chests. They are a lot less common than. Winning a battle has a 25% chance to reward 1x. 1x of them can be converted to 5x in the event shop. 50 are available as a one-time event reward for reaching 250 wins.

Bunker's Ordinary chest is earned as a reward from winning battles, roughly 63% of the time. It has a 100% chance to reward at least 1x.

Bunker's Rare chest is earned as a reward from winning battles, roughly 21% of the time. It has a 100% chance to reward at least 3x.

Bunker's Special chest is earned as a reward from winning battles, roughly 9% of the time. It has a 100% chance to reward at least 6x and a 75% chance to reward at least 1x.

Bunker's Elite chest is earned as a reward from winning battles, roughly 5% of the time. It has a 100% chance to reward at least 7x and a 60% chance to reward at least 4x.

Bunker's Legendary chest is earned as a reward from winning battles, roughly 2% of the time. It has a 100% chance to reward at least 10x and a 60% chance to reward at least 8x.

Bunker fort stats
The bunker also has slots for skins and equipment, but none exist yet.

1 The level 7 damage and accuracy upgrades cost 1500 steel, fuel, and ionites instead.

2 The level 13 health upgrade takes 3d instead.

Brenner event shop
The items available in the shop are as follows. Many of the more powerful items must first be unlocked, by reaching a certain number of Marks of Excellence (you get 1 per win in Brenner) before they can actually be bought. However, unlike most stores, you don't actually have to pay the Marks to unlock the items; rather, the items are automatically unlocked once you reach that number of Marks. However, be aware that Marks do not carry over from one Brenner to another, so make sure to buy everything you want.

End of event rewards
The rewards received at the end of the event are as follows. Note that you have to record at least 1 win in order to receive any rewards.

Artillery bombardment ability
The fort's Artillery Bombardment ability, which is unlocked at fort level 2, works similarly to the artillery bombardment support, but has a different base damage range and fire rate. The fort's version can be used every 30 seconds and shares a cooldown with the fort's Discharge ability. This ability can be improved with three types of upgrades.

The damage of the fort's Artillery Bombardment ability is variable, dealing between 20 and 200 damage per hit with an average damage around 58. Only these six damage values are possible: 20, 30, 40, 60, 80 or 200 damage is possible. It is also possible for the shots to miss completely, dealing zero damage. After testing 100+ direct hits, the table below has the approximate percent for each of these damage values. The damage dealt could be related to how close the target is to the shot. However, since the location of each shot in the volley is random, these damage values are effectively random.

To start an upgrade, each main-line upgrade from the previous levels must be completed first. Each upgrade level is locked until the fort is the same level or higher (e.g. the first "Additional shot" upgrade cannot be researched until the fort is at least level 3).

Healing ability
The fort's Healing ability, which is unlocked at fort level 3, works similarly to the Healing support. The fort's version can be used every 30 seconds and shares a cooldown with the fort's Personal Shield ability. This ability can be improved with three types of upgrades.

To start an upgrade, each main line upgrade from the previous levels (that is, all of those except the ones with a gold border that require Emblems of Valor) must be completed first. Each upgrade level is locked until the fort is the same level or higher (e.g., the first "Increased number of pulses" upgrade cannot be researched until the fort is at least level 2).

Discharge ability
The fort's Discharge ability, which is unlocked at fort level 5, works similarly to the Discharge support. The fort's version can be used every 30 seconds and shares a cooldown with the fort's Artillery Bombardment ability. This ability can be improved with three types of upgrades.

To start an upgrade, each main line upgrade from the previous levels (that is, all of those except the ones with a gold border that require Emblems of Valor) must be completed first. Each upgrade level is locked until the fort is the same level or higher (e.g., the first number of pulses upgrade cannot be researched until the fort is at least level 2).

Personal shield ability
The fort's Personal Shield ability, which is unlocked at fort level 8, works similarly to the Personal Shields support. The fort's version can be used every 30 seconds and shares a cooldown with the fort's Healing ability. This ability can be improved with three types of upgrades.

To start an upgrade, each main line upgrade from the previous levels (that is, all of those except the ones with a gold border that require Emblems of Valor) must be completed first. Each upgrade level is locked until the fort is the same level or higher.

Garrison


The garrison ability appears at level 7 of the fort, and the garrison unit appears after 30 seconds of battle (originally level 10 and 3 minutes, but this was updated soon after the initial release). Currently the machine gun is the one garrison unit available. It has the following base stats: 400, 40 , 75 , 50 , 15 , and 0.5. The health and damage of the machine gun can be upgraded as follows: