Monster Summoning System

The  is a pet system in Ragnarok Online II that combines the buff benefits of Ragnarok Online's Cute Pet System with the debuff and offensive capabilities of its mercenary system. Summoned monsters cannot be controlled by the player; they're truly pets with minds of their own.

Summoning a Monster
Monsters drop 4 different DNA fragments: A, T, G, and C. You need all four from one monster and a Binding Protein in order to create that monster's DNA. DNA is basically the summon's EXP, which you need to level it up.

1 DNA = 1 EXP
 * Level 1 -> Level 2: Requires 29 DNA pieces
 * Level 2 -> Level 3: Requires 99 DNA pieces
 * Level 3 -> Level 4: Requires 199 DNA pieces

Once the monster gains enough DNA to level up, you can now summon the monster. A monster needs to be at least Level 1 in order to be unlocked for summoning. Once summoned, the monster will be out for a maximum of 30 seconds.

Every monster shares the same cooldown, which can be lowered by filling up your Achievement Progress bar. As of now on iRO2, the Base Cooldown starts at 120 sec, and can be lowered to a minimum of 30 sec. The current formula for the Base Cooldown of the pets is: "MAX(30,CEILING(120-90*Number_of_pets_unlocked/98,10))"

Training Your Monster
Summoned monsters' attack ability scales with monster’s class, level, and a percentage of the summoner’s attack or magic power.

Increasing the Max Level
When you first start using the, the max level you can level a monster to is Level 1. You can only increase the max level of any one monster by unlocking other monsters on the Monster Summon List. Once you've unlocked a certain percentage of the list, you'll be able to level up the monsters of your choice to the next level.

Currently, on iRO2, the max level you can level a monster follows this rule:
 * 0-59% of total monsters collected: Level 2 Max
 * 60%-99% of total monsters collected: Level 3 Max
 * 100% of total monsters collected: Level 4 Max
 * 0-66 monsters collected: Level 2 Max
 * 67-97 monsters collected: Level 3 Max
 * 98-189 monsters collected: Level 4 Max

Monster Summon List
Pets that give buffs remain stationary and don't move or attack from their summoned spot.

Pets that debuff move and also help attack the target.

All buffs, debuffs, and special abilities that pets use have an Area of Effect (AoE), except for those stating they are single-target only.

Cute Pets
The was modified to allow the creation of companion pets that mimic the Cute Pet system of RO. Unlike summoned monsters, pet monsters will not despawn after 30 seconds. Instead they will remain around the player until the player changes maps, logs out, or summons a different pet. If the pet disappears, players simply need to resummon the pet from the pet tab of the window to get it back out again.

How to Get a Pet
Players still have to collect DNA pieces from the respective monsters, but instead of using a Binding Protein, players must now combine the DNA pieces with a PluriEgg Blank. Doing so will produce a Pet Egg instead of DNA.

Just like RO, Pet Eggs in RO2 require the use of an incubator to hatch. There are 2 types of incubators available to players:
 * Basic Incubator
 * Golden Incubator

Incubating an egg results in Hatched Eggs, which are necessary to increase the Loyalty of each pet monster.

Patches

 * iRO2 Patch (2018 Jun. 25)
 * Kafra Employees now have Basic Incubators for sale!
 * Treasure Hunter Munil will now trade Basic Incubators for Chance Coupons!
 * iRO2 Patch (2018 Apr. 30)
 * Added alternative pet system to the Monster Summoning System.
 * iRO2 Patch (2017 Jan. 18)
 * Pet names in Monster Collection should now be sorted alphabetically.
 * iRO2 Patch (2013 Nov. 02)
 * Pet Stun and Freeze skills no longer work on dungeon bosses.