SCHG How-to:Add a Homing Attack in Sonic 3 and Knuckles

(Original guide by Sonic Pro1)

first you must have a code editor and the dissambly: sonic 3 & knuckles

I recommend context

well you should go to sonic3k.asm

then go to ; loc_119F6: Sonic_InstaShield:

and sticks

loc_119F6

Sonic_InstaShield: btst #Status_Shield,status_secondary(a0) ; does Sonic have an S2 shield (The Elementals were already filtered out at this point)?

bne.w locret_11A14 ; if yes, branch

btst #Status_FireShield,status_secondary(a0) ; does Sonic have a Homing Attack?

move.b #0,(Shield+anim).w

move.b #1,double_jump_flag(a0)

move.w $650.d0

btst #Status_Facing,status(a0) ; is Sonic facing left?

beq.s loc_11958 ; if not, branch

neg.w d0 ; reverse speed value, moving Sonic left

loc_11958:

move.w d0,x_vel(a0) ; apply velocity...

move.w d0,ground_vel(a0) ; ... both ground and air

move.w #0.y_vel(a0) ; kill y-velocity

move.w .$2000,(H_scroll_frame_offset).w

bsr.w Reset_Player_Position_Array

move.w '-$4A,d0; play homing-attack sound

jmp (Play_Sound_2).l

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And go higher where this is:

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loc_1192C:

Sonic_FireShield:

and replace that with this:

loc_1192C

Sonic_FireShield:

btst #Status_Invincible,status_secondary(a0) ; first, does Sonic have invincibility?

bne.w locret_11A14 ; if yes, branch

btst #Status_FireShield,status_secondary(a0) ; does Sonic have a Fire Shield?

beq.s Sonic_LightningShield ; if not, branch

move.b #1,(Shield+anim).w

move.b #1,double_jump_flag(a0)

move.w #$800,d0

btst #Status_Facing,status(a0) ; is Sonic facing left?

beq.s loc_8CB09 ; if not, branch

neg.w d0 ; reverse speed value, moving Sonic left

loc_8CB09:

move.w d0,x_vel(a0) ; apply velocity...

move.w d0,ground_vel(a0) ; ...both ground and air

move.w #0,y_vel(a0) ; kill y-velocity

move.w #$2000,(H_scroll_frame_offset).w

bsr.w Reset_Player_Position_Array

move.w #$43,d0 ; play Fire Shield attack sound

jmp (Play_Sound_2).l

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ready you already have a semi-homing attack in sonic 3 I hope you have fun and that you are happy