Upgrade

Upgrading is the process of spending Experience and other Account Resources to improve Schematics, Heroes, Survivors and Defenders.

The game offers various ways in which these items can be upgraded.

Level Up

Schematics and People (Heroes, Survivors and Defenders) can be increased in level by spending Experience on them. Each item can be leveled up to its current maximum level. Increasing the level will improve stats and Power Level.

The type of Experience (short: XP) used depends on the item. Weapon and Trap Schematics use Schematic XP, Survivors and Lead Survivors can be leveled up with Survivor XP, Heroes and Defenders require Hero XP.

The amount of XP required for level-up increases linearily with level. For each item type and rarity, there is a 'Base XP' amount which is the first level-up cost (from level 1 to level 2). For each additional level-up, this amount is again added to the previously required amount. Therefore, the required XP to level an item from level X to X+1, is given by BASE_XP * X.

Base XP

Rarity	Heroes, Weapons, Traps, Survivors, Lead Survivors	Defenders
Common	100	50
Uncommon	150	75
Rare	200	100
Epic	250	125
Legendary	300	150
Mythic	400 (Heroes: 300)	N/A

To calculate the cumulative amount of XP required to level an item from level X to level Y (disregarding Evolutions), the following formula can be used:

BASE_XP * ( Y*(Y-1) - X*(X-1) ) / 2

Items inside the Collection Book can also be leveled and evolved. This further increases the Collection Book level.

Evolution

Evolution can be done by spending Experience and Evolution Resources to upgrade a Schematic or People to a higher Star Level. This can only be done when the item is at the maximum level.

Items start at Star Level 1 with a maximum level of 10. Increasing the Star Level will improve stats and Power Level and increase the maximum level by 10.

Items with higher Rarity have a higher limit of Star Level, up to 5 for Epic and above.

Crafting Ingredients for Schematics will also evolve to use higher end Materials.

Resources used in Evolution include:

• Pure Drop of Rain
• Lightning in a Bottle for 3-Star Evolution and above
• Eye of the Storm for 4-Star Evolution and above
• Storm Shard for 5-Star Evolution
• Training Manual for People
• Trap Designs for Traps
• Weapon Designs for Ranged Weapons and Melee Weapons.

The Evolution costs can be read from the following tables:

Heroes, Weapons and Traps

Evolution	Resources	Common	Uncommon	Rare	Epic	Legendary	Mythic (Hero)
2-Star (★★)	XP	500	1000	1500	2000	2500	2500
	Pure Drop of Rain	5	7	10	15	20	20
	Manuals / Designs	0	0	1	2	3	3
3-Star (★★★)	XP		2500	3750	5000	6250	6250
	Pure Drop of Rain		14	20	30	40	40
	Manuals / Designs		1	3	5	8	8
	Lightning in a Bottle		5	7	9	11	11
4-Star (★★★★)	XP			6000	8000	10000	10000
	Pure Drop of Rain			30	45	60	60
	Manuals / Designs			6	9	13	13
	Lightning in a Bottle			14	18	22	22
	Eye of the Storm			7	9	11	11
5-Star (★★★★★)	XP				11000	13750	13750
	Pure Drop of Rain				60	80	80
	Manuals / Designs				12	18	18
	Lightning in a Bottle				27	33	33
	Eye of the Storm				18	22	22
	Storm Shard				9	11	11

Subordinate Survivors

Evolution	Resources	Common	Uncommon	Rare	Epic	Legendary	Mythic
2-Star (★★)	XP	500	1000	1500	2000	2500	7500 *
	Pure Drop of Rain	3	4	6	8	10	12
	Training Manuals	0	0	1	2	3	4
3-Star (★★★)	XP		2500	3750	5000	6250	7500
	Pure Drop of Rain		8	12	16	20	24
	Training Manuals		1	3	5	8	10
	Lightning in a Bottle		3	4	6	8	10
4-Star (★★★★)	XP			6000	8000	10000	12000
	Pure Drop of Rain			18	24	30	36
	Training Manuals			6	9	13	17
	Lightning in a Bottle			8	12	16	20
	Eye of the Storm			4	6	8	20 *
5-Star (★★★★★)	XP				11000	13750	16500
	Pure Drop of Rain				32	40	48
	Training Manuals				12	18	23
	Lightning in a Bottle				18	24	30
	Eye of the Storm				12	16	30 *
	Storm Shard				6	8	10
		* Values in red fields violate the standard pattern of required evolution materials.

Lead Survivors

Evolution	Resources	Uncommon	Rare	Epic	Legendary	Mythic
2-Star (★★)	XP	1000	1500	2000	2500	3000
	Pure Drop of Rain	6	9	13	18	23
	Training Manuals	0	1	2	3	3
3-Star (★★★)	XP	1875	3250	4625	6000	7375
	Pure Drop of Rain	12	18	26	36	46
	Training Manuals	1	3	5	8	8
	Lightning in a Bottle	4	6	8	10	12
4-Star (★★★★)	XP		4750	6875	9000	11125
	Pure Drop of Rain		27	39	54	69
	Training Manuals		6	9	13	13
	Lightning in a Bottle		12	16	20	24
	Eye of the Storm		6	8	10	12
5-Star (★★★★★)	XP			9500	12500	15500
	Pure Drop of Rain			52	72	92
	Training Manuals			12	18	18
	Lightning in a Bottle			24	30	36
	Eye of the Storm			16	20	24
	Storm Shard			8	10	12

Defenders

Evolution	Resources	Common	Uncommon	Rare	Epic	Legendary
2-Star (★★)	XP	250	500	750	1000	1250
	Pure Drop of Rain	2	3	5	7	10
	Training Manuals	0	0	1	2	3
3-Star (★★★)	XP		1250	1875	2500	3125
	Pure Drop of Rain		7	10	15	20
	Training Manuals		1	3	5	8
	Lightning in a Bottle		2	3	4	5
4-Star (★★★★)	XP			3000	4000	5000
	Pure Drop of Rain			15	22	30
	Training Manuals			6	9	13
	Lightning in a Bottle			7	9	11
	Eye of the Storm			3	4	5
5-Star (★★★★★)	XP				5500	6875
	Pure Drop of Rain				30	40
	Training Manuals				12	18
	Lightning in a Bottle				13	16
	Eye of the Storm				9	11
	Storm Shard				4	5

Upgrading item rarity

The Rarity of Heroes and Schematics can be increased by one step in rarity at a time, provided that:

• The item is of Epic or lesser rarity
• There is an equivalent item of higher rarity in the game

Upgrading the rarity requires Flux:

Target rarity	Flux cost
Uncommon	10 Rare Flux
Rare	100 Rare Flux
Epic	100 Epic Flux
Legendary	100 Legendary Flux

Flux can be bought in the Weekly Item Store.

When upgrading rarity, the item level is preserved. To account for the greater amount of XP and evolution materials necessary to level-up and evolve higher-rarity items, the difference in these resources must be paid to complete the rarity increase (XP for evolutions being an exception). The rationale behind this mechanic is that it should make no difference in resource consumption whether an item is first leveled and then 'fluxed', or vice versa.

Upgrading Perks

Perks on Weapons and Traps can be upgraded and modified.

See: Perk Recombobulator