Boss Strike

Boss Strike is a feature that was released in the 3.0 Patch.

Overview
This is a simple walkthrough of Boss Strike for everyone who needs to know how it works. The official explanation can be found here.

Basics
Boss Strike events appear in the upper left of the player's screen, like any other active mission(s). There is a timer associated with this icon that indicates how much time is remaining in the event. Tapping on this icon will load the Boss Strike Event screen.

This screen displays the current Boss Strike event's description and current Tier reward.

The current Tier reward is displayed and the Boss Points progression towards it. Every member of a guild contributes their Boss Points to this progression bar, and every member will be rewarded with the same reward. For this reason, it is most advantageous for players to be part of guilds during Boss Strike events. Soloing is still an option however. Note that players must be at least level 12 to join a guild.

Players earn Boss Points in one of two ways:
 * 1) Donating requested resources
 * 2) FIGHT! - battle and defeating enemy units

Boss Strike Event rewards include units that are unique in that they can only be obtained through Boss Strike Events.

Boss Strike Battles
Selecting the FIGHT! option in the Boss Strike Event screen will start a battle that consists of multiple waves. These battles are equivalent to the player's level, so higher leveled players will face considerably more difficult challenges befitting of their level.

The player can field up to 13 units, which covers the entire battlefield deployment area. In some cases, there are the smaller 3x3 battle maps which only allows the player to field up to 9 units.

Each enemy unit defeated rewards Boss Points. The Boss Points rewarded multiply by a small amount with each subsequent wave.

Once the player loses every unit and is defeated, or defeats every enemy wave, Boss Points are tallied up and awarded to the player. These points are added to the current Boss Point progression towards the current Tier reward. These points also count towards personal Battle Nations achievements. is earned, even if the player's army is completely wiped out. This feature was added in the middle of the second Boss Strike event, on September 6, 2013.

However, if the player retreats, the player is not rewarded with any Boss Points. Players are expected to fight to the last unit in order to earn Boss Points. Units lost in battle are sent to the appropriate Hospital and Repair Bay to await healing/repairs. No  is earned if an army retreats.

Guild Weighting
Your Guild's Boss Strike Point Multiplier will depend on the amount of members your Guild has when the event begins. As your Guild size increase, the bonus multipler will decrease. Below you'll find the exact multiplier for your Guild.

Weight multiplier for Boss Points based on amount of Guild Members:

Sample Battle
The following set of screenshots detail the progress of a Boss Strike battle, as provided by Z2's Poring and a Level 60 Gold Tank army.

The first wave of a level 60 enemy formation. (Differs from player to player even if you're the same level.)

After a few rounds of battle, the Gold Tank army is down to 7 wounded units and is about to destroy the last of the first enemy wave.

Note that the upper left shows the currently accumulated Boss Points from defeated enemy units.

The remaining Gold Tank army now faces the second wave of enemy units.

Retreating at this point would yield no Boss Points, so the Gold Tank army decides to stay and fight.

The Gold Tank is down to its last unit, and defeat is imminent. The enemy delivers the final blow and...

...the Boss Strike battle is over. The player is awarded with the Boss Points that has been accrued from defeated enemy units. The player now has to repair the 13 Gold Tanks.

Events

 * 2nd Lt. Dorian's Assault: August 14–19, 2013
 * The Battle of Shaman Kuros: September 4–9, 2013
 * Boss Enforcer Shrow's Raid: October 3–8, 2013
 * Infected Troops: November 1–7, 2013
 * Yuzul The Raptor Trainer: December 12–17, 2013
 * Evaline Acehart's Airstrike: January 23–28, 2014
 * Shrow's Revenge: February 28–March 5, 2014
 * The Second Battle of Shaman Kuros: March 28-April 2, 2014
 * Rebel Sergeant Ludlow: April 24-29, 2014
 * Dr. Vogel: May 22-27, 2014
 * Rebel Pilot Evaline Acehart's Revenge: June 26-July 1, 2014
 * Raider Boss Strike: July 25-July28, 2014

Trivia

 * Boss strike has a 5 day duration.
 * Boss strike tends to start on Thursday (PST) and end on Tuesday.
 * Boss Strike 11 is special as Z2 has allowed players to choose Units from previous Boss Strikes as Tier rewards in a Facebook poll.