Download Docile NPCs ROM Hack

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)
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TABLE OF CONTENTS

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

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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

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2. REVISION HISTORY

2020-04-18 : Version 1.0 released.
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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.