Final Fantasy III: Docile NPCs

This is a quality of life patch which inclines wandering NPCs to yield ground to the player character.

In the original FF3us, wandering NPCs have a tendency to obstruct player movement. Most noticeably, if the player tries to move into a tile that an NPC is exiting, the player will be blocked if the NPC immediately decides to move back into the same spot.

Now, whenever the player character and an NPC are simultaneously attempting to move into the same empty field map tile, the player character will be given priority, and the NPC's move will be canceled.

This should make navigating though crowded spaces a bit less of a struggle.

Patches for both headered and non-headered ROMs are included in the archive.

Title: Docile NPCs
Author: SilentEnigma
Version: 1.0
Release Date: 2020-04-18
Applies to: Final Fantasy III (v1.0) (U)

Contents:

DocileNPCs-H.ips = the patch for headered ROMs

DocileNPCs-NH.ips = the patch for non-headered ROMs

readme.txt = this file

ROM Addresses: C0/7BB9 - C0/7BBB

Free space used: C0/DB00 - C0/DB48 (49 bytes)
________________________________________________________________________________

TABLE OF CONTENTS

0. Description
1. Relevant Offsets & Disassembly
2. Revision History
________________________________________________________________________________

0. DESCRIPTION

This is a quality-of-life mod for FF3/6 SNES which makes wandering NPCs more
readily yield ground to the player character.

In the original game, wandering NPCs have a tendency to be ever so slightly a
pain in the neck to get around. Most noticeably, if the player tries to move
into a tile that an NPC is exiting, the player may be out of luck if the NPC
decides to move back into the same spot.

Now, whenever the player character and an NPC are simultaneously attempting to
move into the same empty field map tile, the player character is given priority,
and the NPC's move is canceled.

This should make navigating though crowded spaces a bit less of a struggle.

________________________________________________________________________________

1. RELEVANT OFFSETS & DISASSEMBLY

Original:
C0/7BB9: 20 03 7D JSR $7D03
Modified:
C0/7BB9: 4C 00 DB JMP $DB00 ; Jump to new subroutine C0/DB00

New Subroutine C0/DB00:
C0/DB00: 20 03 7D JSR $7D03 ; Originally at C0/7BB9
C0/DB03: AE 03 08 LDY $0803 ; Player character info
C0/DB06: A9 29 LDA #$29 ; Divisor
C0/DB08: 8E 04 42 STX $4204
C0/DB0B: 8D 06 42 STA $4206
C0/DB0E: EA NOP ; Wait for divide
C0/DB0F: EA NOP
C0/DB00: EA NOP
C0/DB11: EA NOP
C0/DB12: EA NOP
C0/DB13: EA NOP
C0/DB14: EA NOP
C0/DB15: AD 14 42 LDA $4214 ; X / A = Player character I.D.
C0/DB18: 0A ASL A ; ...multiply by 2
C0/DB19: A6 1E LDX $1E ; NPC's target tile offset
C0/DB1B: DF 01 20 7E CMP $7E2001,X ; Is player one tile east of NPC's target?
C0/DB1F: D0 04 BNE $DB25 ; Branch if not
C0/DB21: A9 02 LDA #02 ; I.D. for button press Left
C0/DB23: 80 1C BRA $DB41 ; Branch to button test
C0/DB25: DF FF 1F 7E CMP $7E1FFF,X ; Is player one tile west of NPC's target?
C0/DB29: D0 04 BNE $DB2F ; Branch if not
C0/DB2B: A9 01 LDA #01 ; I.D. for button press Right
C0/DB2D: 80 12 BRA $DB41 ; Branch to button test
C0/DB2F: DF 00 21 7E CMP $7E2100,X ; Is player one tile south of NPC's target?
C0/DB33: D0 04 BNE $DB39 ; Branch if not
C0/DB35: A9 08 LDA #08 ; I.D. for button press Up
C0/DB37: 80 08 BRA $DB41 ; Branch to button test
C0/DB39: DF 00 1F 7E CMP $7E1F00,X ; Is player one tile north of NPC's target?
C0/DB3D: D0 07 BNE $DB46 ; Branch if not
C0/DB3F: A9 04 LDA #04 ; I.D. for button press Down
C0/DB41: 24 07 BIT $07 ; Mapped controller input
C0/DB43: F0 01 BEQ $DB46 ; Branch if matching button is not pressed
C0/DB45: 60 RTS ; Skip this NPC move
C0/DB46: 4C BE 7B JMP $7BBE ; Allow this NPC move

________________________________________________________________________________

2. REVISION HISTORY

2020-04-18 : Version 1.0 released.
________________________________________________________________________________

Copyright (C) 2020 David R. Thompson (SilentEnigma).

The copyright holder ("author") permits the free use of the attributed work
referenced by this document exclusively for non-commercial purposes, provided
that the following conditions are met:
1. This readme document shall accompany the attributed work wherever it is
redistributed.
2. The author shall be credited wherever the attributed work referenced by this
document is reused, redistributed, or modified.


Database match: Final Fantasy III (USA)
Database: No-Intro: Super Nintendo Entertainment System (v. 20180813-062835)
File SHA-1: 2F3959057B2AB3664A564C467FBE4B81227CB0F3
File CRC32: 7D91FDF2
ROM SHA-1: 4F37E4274AC3B2EA1BEDB08AA149D8FC5BB676E7
ROM CRC32: A27F1C7A