pokemerald-expansion Vs. Seeker

What is the Vs. Seeker?

The Vs. Seeker is a Key Item that is used to battle Trainers that the player has battled previously.

When used, the Vs. Seeker sends out a signal that allows the player to find other Trainers who want a rematch. This signal affects all Trainers that are on-screen. Once used on Trainers that can be rematched, the device cannot be used again until it is charged. The player does this by walking a specific number of steps. The effect on the Trainers wears off if they are battled, the player leaves the area, or the player walks a specific number of steps. If the player attempts to use the Vs. Seeker when it is not fully charged, the player will be told how many steps remain until it is. After the player uses the Vs. Seeker, some Trainers may have their team changed from their first battle.

How is the Vs. Seeker enabled?

Users

Vs. Seeker functionality is enabled by setting I_VS_SEEKER_CHARGING to TRUE.

Players

ITEM_VS_SEEKER can only be used outside of battle. It can be used from the bag or registered to be used from the field.

Usage of the Vs. Seeker will ALWAYS fail unless all of the conditions are met:

• Player has at least five badges
• There is an NPC on screen that has previously been defeated
• Player is not inside of a building
• The Vs. Seeker is fully recharged

Charge

If the player has ITEM_VS_SEEKER and at least five badges, the Vs. Seeker will be charged by walking steps. The Vs. Seeker is fully charged once the player has walked VSSEEKER_RECHARGE_STEPS, which is 100 by default. The Vs. Seeker’s charge is depleted if the player uses the item.

How does Match Call interact with the Vs. Seeker?

When I_VS_SEEKER_CHARGING is enabled, the Match Call does not function at all. Trainers will never be rematch eligible outside of the use of the Vs. Seeker.

How does the Vs. Seeker choose a Trainer?

When the Vs. Seeker is successfully used, every Trainer on screen is individually queried. There is a 31% chance that the Trainer will want a rematch. Objects listed in regularTrainersOnLand or regularTrainersInWater are considered Land/Water objects.

Rematch Table

The game determines which version of the Trainer you’ll fight next by following these rules:

1. Start with the next Trainer in the sequence after the one that has been defeated. If there are no more, the battle is against the last listed Trainer.
2. If that next Trainer hasn’t been unlocked yet, the battle is against the latest available unlocked version.
3. If the next Trainer is unlocked but not yet defeated, the battle is against that version.
4. If the next Trainer has already been defeated, check the next one in the sequence.

How do users implement rematches with the Vs. Seeker?

Existing pokemerald Trainers

No extra work is required. With the exception of Wally, Gym Leaders and Elite Four, all of the rematchable Trainers in Emerald will work with the Vs. Seeker without any changes.

New Trainers

Party / gRematchTable

Each of the rematches for the Trainer must be defined as seperate Trainers in src/data/trainers.party and include/constants/opponents. For example, TRAINER_CALVIN_1 also has TRAINER_CALVIN_2,TRAINER_CALVIN_3,TRAINER_CALVIN_4, and TRAINER_CALVIN_5.

Once all of those constants and parties are defined, a new row must be added to gRematchTable (located in in src/battle_setup.c). The row header should be a rematch ID, which can be added in include/constants/rematches.h. The row contents must be the five constants created for the new parties, with the lat argument being the constant of the map (include/constants/map_groups.h) where the Trainer is placed.

If a Trainer is intended to have less than five unique rematch parties, the extra slots can be filled with the last available Trainer ID.

// This Trainer only has two teams.
    [REMATCH_ROSE] = REMATCH(TRAINER_ROSE_1, TRAINER_ROSE_2, TRAINER_ROSE_2, TRAINER_ROSE_2, TRAINER_ROSE_2, MAP_ROUTE118),

WARNING: Rematch IDs should be placed BEFORE REMATCH_WALLY_VR. Trainers below that are treated as “special Trainers” that are not triggered by the Vs. Seeker.

Scripts

The trainer’s object needs to have a script that begins with a method to signify what this object’s trainer ID is.

trainerbattle

Route103_EventScript_Daisy::
    trainerbattle_single TRAINER_DAISY, Route103_Text_DaisyIntro, Route103_Text_DaisyDefeated
    msgbox Route103_Text_DaisyPostBattle, MSGBOX_AUTOCLOSE
    end

Daisy is using one of the trainerbattle macros, which has the trainer battle macro in the first command of the script. Most trainers in pokeemerald use this pattern.

vsseeker_rematchid

Route102_EventScript_Calvin::
    vsseeker_rematchid TRAINER_CALVIN_1
    applymovement LOCALID_CALVIN, CalvinMovementTest
    waitmovement 0
    trainerbattle_single TRAINER_CALVIN_1, Route102_Text_CalvinIntro, Route102_Text_CalvinDefeated, Route102_EventScript_CalvinRegisterMatchCallAfterBattle
    specialvar VAR_RESULT, ShouldTryRematchBattle
    goto_if_eq VAR_RESULT, TRUE, Route102_EventScript_CalvinRematch
    setvar VAR_0x8004, TRAINER_CALVIN_1
    specialvar VAR_RESULT, IsTrainerRegistered
    goto_if_eq VAR_RESULT, FALSE, Route102_EventScript_CalvinTryRegister
    msgbox Route102_Text_CalvinPostBattle, MSGBOX_DEFAULT
    release
    end

If the trainer has other script commands before the eventual trainerbattle macro, the first command in the script needs to be vsseeker_rematchid. This macro does nothing but takes a single argument, which should be the same as the first Trainer ID for this trainer.

MOVEMENT_TYPE_COUNTER_CLOCKWISE

If you want Trainers to spin once they are eligible for a rematch, their overworld graphics object ID (include/constants/event_objects.h) must be listed in either regularTrainersOnLand or regularTrainersInWater.Otherwise they will adopt the movement type MOVEMENT_TYPE_FACE_DOWN.

What can be customized about the Vs. Seeker?

• Unlock Conditions: The next “level” of rematches is unlocked when a specific flag is set. The flags that are currently used in GetGameProgressFlags can be changed to flags that better suit your game.
• Recharge Steps: VSSEEKER_RECHARGE_STEPS is initally set to 100, but this value can be changed to any number under 256.
• Badge Requirement: HasAtLeastFiveBadges is used to check if the Vs. Seeker will successfully work. You can customize the number of badges by changing REMATCH_BADGE_COUNT or otherwise alterting the function.

What are the limitations of the Vs. Seeker?

The Vs. Seeker does not currently work with Gym Leaders. There is a bug filed to hopefully fix this in the future.