Frost Moon

The Frost Moon is a Hardmode, post-Plantera, Christmas-themed event summoned with the Naughty Present at any time at night, ending at dawn (4:30AM). It can be summoned at any time of the year and does not require the actual Christmas season. During the event, unique and highly difficult enemies spawn at high rates and attack the player. It is similar to the Pumpkin Moon event, but consists of more waves and includes slightly more content. Visually, the moon turns into a snowman head, though remaining in its current phase.
The entire event consists of 15 waves, plus 5 "bonus waves". Waves progress as the player reaches certain kill scores (though kill scores are not displayed to the player before wave 20). After a wave's required score is met, the next wave begins, and the kill score is reset to 0. Status messages will indicate when the wave has advanced, and which wave has been achieved. See the table below for the points awarded for each enemy and the score required for each wave.
The Frost Moon event always ends at 4:30 AM. The goal of the event is to progress through all 20 waves before the event ends, although the achievement for the event is awarded at wave 15.
The Naughty Present, which summons the Frost Moon, requires materials only available in Hardmode worlds where the player has already defeated Plantera (although it can still be summoned in pre-Hardmode worlds). As such, it is intended to present a challenge even to players with the best possible equipment. In the final waves, multiple boss-level enemies are fought at once.
Frost Moon enemies drop powerful weapons, as well as pet and vanity items. Most drop with extreme rarity, and even players who manage to complete the event will find they need to do so several times before obtaining them. Drop chances for items dropped by bosses increase as waves are completed. See the section below for a more detailed description of the rates at which loot and trophies drop.
Reaching wave 15 / 20 before 4:30 AM will display the message “” at dawn (4:30 AM). For the entire day and night, all special effects of the Christmas season will occur. At 4:30 AM of the next day, the message “” will appear and all Christmas events will no longer occur until the Christmas season begins again or the player reaches the 15th wave of the Frost Moon again. 
==Contents==
==Waves==
 Points per kill 
Enemy 	Points
Zombie Elf 	1 /
Gingerbread Man	2 /
Elf Archer 	3 /
Nutcracker 	4 /
Flocko 	0 5
Elf Copter 	8 /
Krampus 	0 10
Yeti 	18 /
Present Mimic 	20 /
Everscream 	50 /
Santa-NK1 	100 /
Ice Queen 	150 /
 Wave scores & enemies 
Wave	Points required	Enemies
1 	0 	Zombie Elf and Gingerbread Man
2 	25 	Zombie Elf and Elf Archer
3 	40 	Zombie Elf, Elf Archer, Gingerbread Man, and Nutcracker
4 	50 	Everscream, Zombie Elf, Elf Archer, and Gingerbread Man
5 	80 	Everscream, Zombie Elf, Elf Archer, and Nutcracker
6 	100 	Everscream, Elf Archer, Nutcracker, and Elf Copter
7 	160 	Santa-NK1, Gingerbread Man, Elf Archer, and Zombie Elf
8 	180 	Santa-NK1, Elf Copter, Elf Archer, Nutcracker, and Krampus
9 	200 	Santa-NK1, Everscream, Nutcracker, Elf Copter, and Gingerbread Man
10 	250 	Santa-NK1, Everscream, Krampus, Zombie Elf, and Elf Copter
11 	300 	Ice Queen, Flocko, Zombie Elf, and Gingerbread Man
12 	375 	Ice Queen, Everscream, Gingerbread Man, Yeti, and Zombie Elf
13 	450 	Ice Queen, Santa-NK1, Elf Copter, Gingerbread Man, and Flocko
14 	525 	Ice Queen, Santa-NK1, Everscream, Yeti, and Krampus
15 	675 	Ice Queen, Santa-NK1, Everscream, Yeti, and Elf Copter
16 	850 	Ice Queen, Santa-NK1, Everscream, Yeti, and Flocko
17 	1025 	Ice Queen, Santa-NK1, Everscream, Yeti, Krampus, and Elf Copter
18 	1325 	Ice Queen, Santa-NK1, Everscream, Yeti, Nutcracker, and Krampus
19 	1550 	Ice Queen, Santa-NK1, Everscream, and Yeti
20 	2000 	Ice Queen, Santa-NK1, and Everscream
 
*Total points required to reach wave 15: 3410, wave 20: 10160
*Present Mimics may spawn at any wave, instead of wave-appropriate enemies, if there are currently less than four Present Mimics around.
*The maximum number of bosses at once depends on the wave. While this number is reached (or possibly exceeded, for example if the player manages to somehow reach wave 9 without killing two Everscreams from wave 6), no more of this type of boss will spawn.
:
Boss spawn limits 
Wave	Everscream	Santa-NK1	Ice Queen
4 	1 	 	
5 	1 	 	
6 	2 	 	
7 	 	1 	
8 	 	1 	
9 	1 	1 	
10 	1 	2 	
11 	 	 	1
12 	1 	 	1
13 	 	1 	1
14 	1 	1 	1
15 	3 	2 	1
16 	4 	2 	2
17 	5 	3 	2
18 	6 	4 	3
19 	7 	5 	4
20 	Unlimited 	Unlimited	Unlimited
===Loot===
*All of the boss-type enemies (Ice Queen, Santa-NK1 and Everscream) have increased chances to drop loot in later waves. This chance starts at 10% () in wave 4, and grows at a nonlinear increasing rate up to 16.67% () by wave 15, continuing to 25% () by wave 20.
**The above chance does affect trophies on ; it does not affect them on .
**The exact formula for the drop chance is as follows:
**:{{math|Frost_Moon-math-1|{{#uesc:<esc>\frac{1}{\max(\left \lfloor \frac{30 - W}{2.5} \right \rfloor - E,\ 1)}</esc>}}|inline=y}}
**:with W = current wave number (plus 7 if in ), and
**: with E = 0 or .
**:This chance is affected by .
*In all versions, trophies have their own, separate chance to drop (which, on , also applies alongside the general drop chance, as explained above). Starting at wave 15 (or, on , at in Expert Mode), there is a chance each Ice Queen, Santa-NK1 and Everscream killed will drop its respective trophy. This chance increases at wave 17, and again at wave 19; on in Expert Mode, these increases instead happen at wave 10 and at wave 12, respectively. On , Luck does not affect this chance. The trophy drop rates for each version in each wave are shown in the table below.For trophies, Expert Mode has a chance of reducing the denominator by 1 compared to Classic Mode; e.g. in Expert Mode on wave 15 on (or on wave 8 on ), there is a 2/3 chance that the drop rate will be (25%), but a 1/3 chance that the drop rate will be ; thus, the average of these outcomes is {{math|Frost_Moon-math-2|{{#uesc:<esc>\frac{1}{\frac{\left(4+4+3\right)}{3}}</esc>}}|inline=y}} ≈ 27.27%; this does not take into account the overall item drop chance. 
:
Wave 	Trophy chance	Actual trophy drop rate	Actual trophy drop rate	Actual trophy drop rate
Wave 	Trophy chance	 	 	
15 / 	 	 	 	
16 / 	 	 	 	
17 / 	 	 	 	
18 / 	 	 	 	
19+ /	 	 	 	
==Notes==
*The Frost Moon event will sometimes end after leaving and then reentering the world.
*On the , Everscream, Santa-NK1 and Ice Queen can drop their trophies as early as wave 8 in .
*Water Candles, Peace Candle, Battle Potions and Calming Potions have no effect during the invasion, as the same with some other events.
* If the player is killed during the event, the event is not canceled. The player will keep re-spawning and can continue fighting its enemies as the event continues until dawn. In single-player games, exiting the world and reloading it will cancel the event, but it will also delete the items from the ground.
*The Frost Moon does not stack with the Blood Moon. Summoning the Frost Moon while a Blood Moon is active will result in a regular Frost Moon.
*Summoning a Pirate Invasion during a Frost Moon will cancel it.
*Any boss enemies that are still on a player's screen by the time dawn breaks will begin to move rapidly in a single direction, rushing off-screen to despawn. It is still possible to pursue or even kill some bosses while this is occurring.
*Lingering enemies beaten after the event is over will never drop any rare items.
==Achievement==
==Tips==
* Because spawn rates for areas where Frost Moon enemies cannot spawn are also increased, a Frost Moon can be used to farm for other items, e.g., Pirate Maps at the Ocean, while completely avoiding the Frost Moon enemies.
*The Frost Moon enemies are susceptible to the Ichor debuff, which makes a Flask of Ichor, Ichor Arrows or Bullets, or the Golden Shower very effective.
*Players should kill the enemies as soon as they spawn to ensure that more enemies can spawn continuously in order to increase the chances of reaching later waves.
*The Frost Moon can be a great way to obtain a large amount of coins quickly.
*A good potion to use is the Warmth Potion as it decreases damage significantly from enemies in the event.
==Trivia==
*On the , the Frost Moon is often considered the hardest event in the game.
**The , which are not available on those versions, are substantially more difficult.
*This is one of the few post-1.2 features available on the .
*The soundtrack for the Frost Moon strongly resembles and was potentially inspired by the Trans-Siberian Orchestra, a Winter/Christmas themed rock band.
*Unlike its Halloween-themed counterpart, Pumpkin Moon, this event does not drop a summon weapon. 
==History==
==References==
Category:Summoned events