Blood on the Snow

"Blood on the Snow" is the special Christmas event. It was first launched December 20, 2019, running for three weeks. In 2020, it appeared again on December 24, with new shop items and slightly reduced fuel costs; in 2021, the event was open again from December 23 to January 14, 2022, with no changes from the 2020 version. It also appeared for the 2022 season from December 15, 2022 to January 12, 2023, again with no new changes. In it, you can fight in a special event campaign in normal and heroic modes, and use the rewards to decorate your base's Christmas tree to earn special rewards. For the official details, you can see the official post.

## Campaign

The campaign contains a total of 19 areas. The first is unlocked, but the rest are locked and must be unlocked by paying either ice steel gears (sometimes also called "froststeel gears") or Klausbot powerslots (sometimes also called "power cells" or "energy cells"). You can unlock the areas in any order (especially useful to skip the areas that require power cells, because those are harder to get). Unlike a normal campaign, you can redo the missions to get more rewards, but you have to wait for a cooldown timer before you can attack the mission again. Beating a mission earns you some number of gears and a chest with Christmas ornaments (described below); most missions have a chance to also earn a power cell, although this chance is quite low. If you don't have the necessary number of gears or power cells to unlock a level, you can also pay with gold, at the cost of 50 gold per missing gear or 150 gold per missing power cell.

The rules for how chest drops work on each level are as follows:

* If a level only drops one kind of chest (all levels through "Deaf defense"), then you always get that chest.
* If a level drops more than one kind of chest, but does not drop power cells ("Absolute zero" and "Shock wave"), then you always get exactly one chest, with the probabilities listed below.
* If a level drops more than one kind of chest, and does have a chance for power cells (the rest), then you can get a maximum of two items between the power cell and chests (that is, if you get a power cell, you will only get one chest, but if not, you have a chance to get two chests). The probabilities listed below take this limit into account. You are always guaranteed at least one chest, however.
* The last mission, "Savior", initially worked the same way as above. With the release of Star Boxes in the January 8 update, it was changed to drop a maximum of 3 boxes, which means that the drop chances of the first three boxes are independent, and you are guaranteed a Star Box I **unless** all three other chests drop (this is taken into account in the probabilities below).

For full details on the missions, see the "Detailed mission information" section below.

The enemies you face are as follows:

* LK-48 (infantry): Relatively standard infantry, although with only four per squad.
* FD-42 (stormtroopers): Relatively standard stormtroopers.
* HK-17 (heavy infantry): These units have a long-range howitzer which can do splash damage, making them dangerous against groups of your units.
* KD-34 (special): The are robotic wolves which carry guns on their back, allowing them to fire from medium range with a good rate of fire.

In later levels the enemy will also drop turrets and in the last three levels they can drop Modernized Turrets as well.

## Heroic mode

Heroic mode is an even greater challenge. In heroic mode, you must beat the levels one by one, with each victory unlocking the next level. You have a total of 2 hours 30 minutes (starting from when you start the first battle) to complete the heroic mode. Each heroic mode battle awards you central ionite processors, which you can use to buy powerful rewards in the shop. If you run out of time, or fail a total of 3 times, then your attempt ends. If you succeed, you receive a bonus of 50 processors per attempt you have remaining. In either case, you must wait 16 hours for the event to reset. You can also recover failed attempts with Gold, at the cost of 50 per attempt. (Note that your run doesn't end immediately if you fail a 3rd time, in case you do want to recover a failure. You can choose to immediately end your run at this point, however.)

The heroic battles are significantly different from standard battles. You cannot take any regular units into battle; instead, your lineup consists of 5 heroes and 11 support units. These support units also cannot be anything that generates new troops, such as landings. The heroes do not all start on the battlefield, but instead appear in a special area in the top right of your screen where you can select and deploy them at will. The support units that you bring are used as normal.

With the release of Star Boxes in the January 8, 2020 update, the last HM battle ("Savior HM") also drops a Star Box II.

All heroic mode missions have a recommended level of 15+. The fuel cost starts at 150 per mission and increases by 25 for each. In general, you will need at least 2-3 very strong heroes in order to even have a chance with these missions, as they are very difficult.

The enemy troops are different from the regular missions, and are extremely powerful:

* Klausbot model Infantryman v.2 (five melee units)
* Klausbot model Stormtrooper v.2 (three melee units with frost aura skill)
* Klausbot model Vanguard v.2 (one melee unit with shield)

In addition, the enemy will use supports including Minefield, carbonite bomb, Ionite Carbonite Bomb, and Unstable Carbonite Bomb. On and after map 9, the enemy will start to use Armageddon as well.

A full heroic run (without any defeats) will cost you 7025 fuel and will net you 100 central ionite processors (for clearing all maps) as well as another 50 processors for each unused try, for a total of 250 processors.

The heroic mode maps also have different descriptions; for details, see the "Heroic mode descriptions" section below.

## Shop

The items available in the shop are as follows. In the initial 2019 release of the event, the more powerful items had to first be unlocked by paying a certain number of power cells before they could be bought, but these unlock costs were removed in the 2020 version.

## Christmas tree

During the Christmas event, your base features a Christmas tree. Decorating the tree will increase its level, which entitles you to more daily and one-time rewards.

To decorate your tree, you need decorations. The decorations drop from Christmas boxes as follows. In all cases, you have an equal chance of each possible item:

* Children's toy box: 1 level I garland, present, ornament, or star (approximately 6% chance of each)
* Box with christmas ornaments I: 1 level I garland, 1 level I present, and 1 level I ornament
* Box with christmas ornaments II: 1 level II ornament, 1 level I or II garland, and 1 level I or II present
* Box with christmas ornaments III: 1 level III garland, 1 level II or III ornament, and 1 level II or III present
* Box with christmas ornaments IV: 1 level IV present, 1 level III or IV ornament, and 1 level III or IV garland

(Note: in the boxes, it looks like the Carbonite "Souvenir" and "First Aid Kit" are swapped -- you can receive a "Souvenir" in the present slot even though it's actually an ornament, and vice-versa.)

The January 8, 2020 update also added Star Boxes, where Star Box I drops from the final mission, and Star Box II drops from the final heroic mode mission. They are guaranteed to contain a star, along with other items:

* Star Box I: Star III (15%) or II (85%); 1 level III or IV ornament; and 1 level III or IV garland
* Star Box II: Star IV (15%) or III (85%); 1 level III or IV ornament; 1 level III or IV garland; and 1 level IV present

You can also exchange decorations to get higher-level decorations; five of any decoration (they don't have to be the same) of one level can be traded for one random decoration of the next level up. (You can also get higher-level stars in this exchange.) Stars, however, can only be upgraded along with other stars for higher-level stars.

The decorations come in four different classes, each of which occupies a different spot on your tree:

* Garlands (4 spots, ends of 3rd and 5th rows): "Machine Gun Belt" garland, "Light of the Empire" garland, Ionite garland, "Mutagen" garland, "Scientific Progress" garland
* Presents (4 spots, center three of 5th row and bottom): Box with gifts, Chest with gifts, "First Aid Kit" christmas ornament, Artillery shell
* Ornaments (7 spots, all the rest except for the top): Cross of Influence, "Tesla" bauble, "Turret" christmas ornament, "Gas Mask" christmas ornament, "Hammer" christmas ornament, "Lycanthrope" christmas ornament, "Guardian" christmas ornament, Carbonite "Souvenir"
* Star (1 spot at the very top)

In all cases the name is followed by a Roman numeral indicating the level.

The level of the tree is determined by the total value of all of the decorations, where each level I decoration contributes 1 point, each level II decoration 2 points, etc. Thus, you could reach level 4 (30 points) with 14 level II decorations and 2 level I decorations, or any other combination adding up to 30. In order to get the highest level and unlock the special reward hero Esben Defender, you must have all 16 slots filled with level V decorations. (Note that unlike similar events, the stars are worth the same as regular decorations -- 1 point per level).

As the names suggest, you can claim the daily rewards every day during the Christmas event, while the one-time awards you can claim only once.

## Detailed mission information

 **Strategic points** | 2x Mortar

 **Strategic points** | 1x Machine gun, 1x Mortar

 **Strategic points** | 2x Machine gun, 2x Mortar

 **Strategic points** | 1x Machine gun, 2x Mortar

 **Strategic points** | 2x Machine gun, 1x Mortar

 **Strategic points** | 2x Field healing

 **Strategic points** | 3x Machine gun, 2x Mortar

 **Strategic points** | 3x Machine gun, 2x Mortar

 **Strategic points** | 3x Machine gun, 2x Mortar

 **Strategic points** | 2x Machine gun, 1x Mortar

 **Strategic points** | 2x Mortar

 **Strategic points** | 3x Machine gun, 1x Mortar

 **Strategic points** | 5x Machine gun, 1x Mortar

 **Strategic points** | 2x Machine gun, 2x Mortar

 **Strategic points** | 2x Machine gun, 1x Mortar, 1x Victorious courage

 **Strategic points** | 4x Mortar, 2x Field healing

 **Strategic points** | 3x Machine gun, 2x Mortar, 1x Victorious courage

 **Strategic points** | 2x Mortar

 **Strategic points** | 4x Mortar, 1x Field healing

## Heroic mode descriptions

Here are the descriptions for the heroic mode maps:

* Distant line HM: *Six months ago, Captain Walker established a defence treaty of mutual assistance with the northern tribes against Crimson Dominion and raiders. In a short period of time, joint efforts in the region brought order backed up until recently by northerners. Over the past month, the Resistance lost two convoys with ionite. Commander Grant believes it's time to meet with the alies and find out who is behind these attacks ...*
* Alarming news HM: *Right behind Eden Bay, where permafrost reins, Resistance troops were about to meet with the local tribes. To check the path for safety, Captain Walker sent several groups of rangers for reconnaissance. A few hours later, we received a one-word message from them: "bots", and communication line went dead. But they were lucky to activate an alarm with a rescue beacon indicating their location.*
* Border mobilization HM: *Figuring that "bots" means "robots", the captain decided to advance at an accelerated pace to the beacon signal. In conditions of extremely low temperature, beacon spent its charge much faster than usual and therefore it was necessary to get there before the power will be down. But as soon as the Imperials advanced in the indicated direction, robots appeared on the horizon.*
* Dominion counterattack HM: *Scouts were right! These are not ordinary robots - these are bots! A year ago, on the northeastern outskirts of the Western sector, the Resistance forces destroyed Klausbot - a robot created by a crazy scientist who almost single-handedly killed the 2nd shock army. Those mechanisms that just showed up at Eden Bay, although much weaker, are clearly created on the basis of Klausbot. And if so, then the scientist kept his promise and returned, creating himself a new army.*
* Heartless enemy HM: *The beacon signal went down just at the moment when the Resistance troops reached the battlefield between the bots and the rangers. As soon as the Resistance fighters approached the bodies of their fellow soldiers, bots began to rise from all sides from under the snow. It seems that they clearly knew about the rescue beacon - or maybe... they turned it on themselves*
* "Hostage" HM: *Breaking out of the ambush, the Imperials rushed further north - they needed to cross the Eden Bay as soon as possible and meet with the local tribes. A few kilometers away from the Dun Heim Rocks soldiers were expecting to meet the observation posts of the Uruzgal clan - they were the first ones to see Walker when he arrived to sign the peace treaty six months ago. But in order to get there, Imperials need to defeat the bots first and these bots didn't intend to let them cross to the other side of the bay.*
* Defense preparation HM: *The observation posts of the Uruzgal clan are destroyed, and the snow skirmisher who served here are killed! Bots are following Imperials closely behind. The only way out in this situation is to take up the defense and repulse the mechanisms, and then go further into the Dun Heim Rocks in search of local tribes.*
* Field laboratory HM: *The last bot is destroyed, but there is no time to take a breath and relax. Very soon, new mechanisms will appear. After leaving what remained of the observation posts of the Uruzgal clan, the Imperials headed inland to the Dun Heim Rocks. The last time Walker was here, he followed the guide - but now the captain was on his own. From a long transition and exhausting battles, he got confused and decided to halt, which led to another attack by bots, which, unlike people, did not know fatigue.*
* Machine heart HM: *When the battle was in full swing, members of the local tribes of Parturaz and Tureyvaz arrived for help just in time, guided here by the sounds of the battle. Representatives of the clans said that bots began their regular attacks on local tribes a month ago, killed those who resisted and captured those who weren't armed or couldn't fight. Scouts from the tribes were managed to find out what they came from the Irsguard mines direction. When asked whether the convoys with ionite were also intercepted by bots, the representatives didn't know anything.*
* Deaf defense HM: *While negotiations were ongoing, the bots attacked again. Surrounded by northerners and imperials, mechanisms weren't afraid to come down from the mountains and show thier their "faces".*
* Blood, snow and steel. HM: *When the battle was over, Captain Walker ordered a halt. And then, after teaming up with the warriors of the Parturaz and Tureyvaz clans, the imperial set off towards the Irsguard mines. Apparently, Klaus gave his toys an order - to kill every last one of the people. How else one can explain the fact that more and more bots attacked with every step of their way?*
* Absolute zero HM: *The Dun Heim Rocks are left behind. The combined forces of the northerners and the Resistance reached the road from the Protectorate Valley to Zone X-69. It seems that this is the road that Magnus uses to deliver convoys with ionite to Osterberg. Walker's attention was drawn to the fact that there were completely fresh car tracks along another road in the direction of Irsguard mines. A moment later, new bots appeared from there.*
* Rigor HM: *Having dealt with the bots, the combined forces under the command of Walker soon reached the industrial factory. Near the entrance they saw the New Order truck and captive members of local tribes that where unloading it, Walker noticed that they were unloading boxes with ionite and spare parts. Captives were guarded by other northerners - from the Yeralguz clan. The territory of the factory was patrolled by bots. Without waiting for them to be noticed, Walker ordered to attack.*
* Steel avalanche HM: *People from Yeralguz clan are defending alongside the bots! What does it mean - the whole clan is cooperating with Klaus or only some of its representatives?*
* Shock wave HM: *The factory is seized, and the prisoners are released! Those who are able to hold weapons in their hands have joined the combined army and are eager for revenge! According to former prisoners, this workshop is only part of the large Ardheim factory complex No. 34. Well, then we'll take control of it all!*
* Icy grasp HM: *The rest of the captives are kept not far from the assembly workshops No. 2 and No. 3, which are guarded by "Stormtrooper" type bots - these are elite machines with high mobility and incredible combat power. Defeating them will not be easy - but we need to do this and free the northerners!*
* Steel giant HM: *Prisoners released and joined the united army! Klaus throws his best developments into battle - "Vanguard" is a modified and improved version of Klausbot! These models are standing in the way of the main building. In order not to repeat the fate of the 2nd shock army, one must proceed with caution.*
* No options HM: *Klaus called for reinforcements! Fighters of the Yeralguz clan came to his aid. They attacked the combined forces from the rear! It seems that the entire clan of the northerners went over to the side of the mad scientist voluntarily! And if so, we won't go easy on the traitors who violated the cooperation agreement!*
* "Savior" HM: *The main building is surrounded! Klaus, if he is there, has nowhere to go. It is time to take control of the entire factory complex and destroy the bots of the mad scientist in order to put an end to his equally crazy plans!*

## Mysterious gifts

In the 2019 event, you could use the event shop to send mysterious gifts to your friends (the "?" tab at the top left of the shop window). This feature does not appear to be available in 2020. These gifts are not free -- they cost Kreds to purchase -- but can contain very useful items:

* Elite equipment: 19 Kreds
* Legendary equipment: 49 Kreds
* Skins: 149 Kreds (random skin for base troops, not including special event skins)
* Heroes: 199 Kreds (random non-legendary Hero)