Relay Defense (Japanese:リレー防衛戦Relay Defense Battle) is a game mode inFire Emblem Heroes, and one of a number of types of the game'sSpecial Maps. It is a type of Special Maps that debuted on September 8, 2018, and whose maps rotate on a schedule intertwined with theRival Domains mode; Relay Defense maps useRelay Defense: Event Map, last for two weeks, and their events begin and end on Saturdays at 7:00 AM UTC.

Overview

Relay Defense takes place on larger game maps than normal gameplay, and allow players to deploy teams of up to 20 characters, of which up to five can be on the map at any given time. At the start of every odd-numbered turn, the units the player has on the field at the time are switched out and replaced by the next five characters in line in the same locations, or back at a player's base if one of the units in the quintet being switched out had been defeated. There are some restrictions on character deployment, namely that players may deploy a maximum of one character that can useSing orDance and cannot deploy duplicate characters.

Forming a brigade

Much like Rival Domains andGrand Conquests, in addition to their own characters, players also have the option of deploying characters chosen by those on their friend lists; the character at the top left of a player's first listed team is the one made available to other players. If a player leaves empty slots in their deployment, any missing slots will be filled with a randomly-selected 5★ character chosen from all normal-variation characters available in the regular summoning pools that do not wieldstaves, Sing, or Dance.

Unlike other types of Special Maps, the enemies on Relay Defense maps are randomly generated more in the vein of theTempest Trials, also taken from all normal-variation characters minus performers and staff-wielders in the regular summoning pools, but the enemy army ignores the "no duplicates" rule and fixes its selection to those characters available when the map most recently rotated in (ex. the Event 1 maps did not includeOphelia,Nina,Silas, andFlora as available enemy units as they did not become available until after the map started, but did allow those four characters as player reinforcements as the player reinforcement pool is not bound by the same rule). The enemy army has only twelve units in total, with six present on turn 1 and the other six arriving asreinforcements on turn 2.

Victory

The player's team can make use of two types of special tiles to their advantage, fortresses and camps. Characters can freely warp between fortresses, camps, and three chosen squares adjacent to them. Fortresses can be taken out with three attacks, if the enemy team does so, the battle automatically ends as a loss for the player; camps can be taken out with two attacks, and when this happens, the camp will no longer be usable.

To win a Relay Defense battle, the player's fortress must remain standing throughout all eight turns. The player can accumulate a score during a battle; points are awarded for defeated enemies, surviving allies, the health of the fortresses and camps, and bonus categories that vary per map, and meeting the target score yields rewards.

Difficulty options

Relay Defense has eight "difficulties" available across its eight maps, each one requiring the previous map to be defeated in order to access:

	Enemy level and rarity	Enemy skills	Enemy stat boosts	Rewards
1st Map	3★, Lv. 30	Fourth weapon skill andPivot only	None	×1
2nd Map	4★, Lv. 35	Highest weapon skill andPivot only	HP +5	×500
3rd Map	5★, Lv. 40	Entire skill kit, apart from assist skill which is alwaysPivot	HP +10 Attack/Speed/Defense/Resistance +2 each	×500
4th Map		Entire skill kit, apart from assist skill which is alwaysPivot Weapon skills have gone through theWeapon Refinery whenever possible	HP +10 Attack/Speed/Defense/Resistance +4 each	×10
5th Map			HP +15 Attack/Speed/Defense/Resistance +6 each	×500
6th Map			HP +15 Attack/Speed/Defense/Resistance +8 each	×10
7th Map			HP +15 Attack/Speed/Defense/Resistance +10 each	×1
8th Map			HP +15 Attack/Speed/Defense/Resistance +12 each	×500

List of maps

Note: All date ranges begin at 7:00 AM UTC on the first listed date and end at 6:59 AM UTC on the second listed date.

List of Relay Defense maps
Event number	First-run dates	Map 1/3/5/7	Map 2/4/6/8	Notes
Event 1	September 8, 2018 – September 22, 2018			--
Event 2	October 13, 2018 – October 27, 2018			--

Etymology and other languages

Gallery

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  The banner design used for Relay Defense.
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  Home banner used for Relay Defense.