Trap Event Data Notes


#1


Unfortunately, there is no sound effect.

I couldn’t find the spear trap, but I did find the FE6 ch21x fire trap variation that activates immediately when you wait on it. Also, you can make chapters with pre-placed mines.


Do hallway traps exist in FE7?
#2

Please, do go on.


#3

Fixed the sound issue.
Edit the sound effect ID at 01EF1A. It’s only 1 byte so the sound effect ID can’t be greater than 0xFF. The light arrow sound effect may have been completely removed from FE7. Sound effect 0xB4 (warp noise) is a okay replacement (better than silence at least)

Defining traps in event data:

Instant Fire Trap:
08 XX YY 00 00 00

Mine:
0B XX YY 00 00 00

Vertical Light Arrow:
07 XX 00 00 TT RR

TT = Initial timer. Timer decrements every turn. When timer hits zero, the trap activates.
RR = Repeat timer. After the trap activates, reset timer to this value.
Example: 02 03 would mean the trap first activates on turn 2 then repeats every 3 turns.

Right now there’s no proper routine that will take light arrow trap event data and write it to the 0203A518 section. For testing I just modified/stole the routine that writes the regular fire trap data to 0203A518. Don’t tell anyone.
034628: 88 -> 48 (change routine table)
02BB30: 04 -> 07 (change trap type)


#4

awesome !!!
so pre-placed mines just deal a set 10 damage?
is there a difference between instant fire traps and mines?
And does the lightning arrow deal fixed damage because I remember @L95 saying it deals damage off defense or something


#5

I take it the pre-placed mines suffer from the same control-enemy exploit as player-placed ones?
Also, you’re a stud. Thanks for finding this stuff.


#6

no kidding. This makes me look forward to actually designing chapters around traps.
Thanks so much gryz, looking forward to more discoveries about this


#7

Pre-placed mines deal 10 damage just like regular mines. Instant fire traps activate after the unit acts. Mines activate when units move over them and causes their turn to end. The light arrow deals 10 damage in FE6 and still does fixed damage in FE7.

There is no difference between pre-placed mines and the mine item. They both write the same data to the same place.


So, it turns out the spear trap animations are still in FE7. But it looks like everything else related to their function is gone.

Replace the mine’s animation with the upward spear animation:
At 034306 paste: 03 23 03 23 EA F7 B7 FE
At 01F056 change BB to D4 (or any other 1-byte sound effect)


#8

Actually, there is. It’s just unused in FE7. Good. Now we can easily read light arrow traps from event data.

At 034628 change 88 to 72
At 034674 paste: 29 79 6A 79 F7 F7 72 FA

(At 034674 I am borrowing some unused space which I think was meant for reading spear trap parameters)


#9

So, we have functioning light spears, knife traps and poison vents that aren’t exploitable.
Pre placed mines and fire traps sadly are! :frowning:


#10

We don’t have functioning wall spear traps. I just figured out how to get the animation to play.

New discovery
FE6 chapter 14x uses “trap data” to trigger the chapter’s tile changes. The “trap” uses a timer to automatically alternate between 2 tile changes (and play the bloop sound effect). FE7 chapter 28x uses turn events for its tile changes instead, but the FE6 functionality still exists. Although, like the light arrow trap, the game won’t read it from event data without some tweaks.


#11

Normal fire traps can be disarmed by units with the lockpick ability.

Units with the following abilities can move over mines without being stopped:
lockpick, lethality, pegasus aid icon, wyvern aid icon

Did you know it’s possible to pick up mines? I didn’t!

When a unit ends its turn on a mine tile:
If unit has lethality and an empty inventory slot: remove mine, add mine to inventory
If unit has lethality and a full inventory: nothing happens
If unit has steal ability (and not lethality): nothing happens
Otherwise, BOOM!

So, flying units can safely move over mines but not end their turn on them.


#12

gryz-senpai I think I’m falling for you


#13

I did, but only because I noticed there was a text string for it in FE8, (though I wrongly assumed it was Rogues that could do it) I got really bored this one time and opened FE8 in FEditor and read through all the text in the game. (I was on a road trip don’t look at me like that)

Other things in FE8 that seem kinda random and weird:
Some random names like “Ruthea” (Lucius Japanese name) Lyn, Roy, and Douglas
What I assume are menu options relating to removed debug menus.
very bear


#14

now, i love very bear as much as the next guy, but i think there’s also something to be said for

christ, i wish feditor was compatible with the japanese roms. i have a burning need for anything which could possibly explain what these strings were even meant to be


#15

@Gryz Could you PM me the information about how to define them in events and stuff so I remember to incorporate them into the EA sometime later?


#16

Here are the special tiles that can be read from event data:

               00 01 02 03 04 05
Ballista     : 01 XX YY BL 00 00
Fire Trap    : 04 XX YY 00 TT RR
Poison Trap  : 05 XX YY DI TT RR
Instant Fire : 08 XX YY 00 00 00
Mine         : 0B XX YY 00 00 00

BL = ballista type, DI = direction
TT = initial timer, RR = repeat timer

You can make fire traps and poison traps only trigger on certain turns. Although I would keep the default timers at 01 01. The game also reads special tile 09, but it has no effect (my guess this was meant to be the spear trap)

FE7 simply refuses to read any other special tile type from event data.

The whole process also takes up quite a bit of space. The routine goes through the effort of determining which types to read and which of the 6 bytes to use (instead of just grabbing them all). I rewrote this routine so it reads all special tile types.

Now the following can be read from event data:
06: Alternating tile changes
07: Light arrow trap
0A: Torch staff beacon (with variable vision radius)
0C: Light Rune (with variable duration)

Special tile type 02 is snag/cracked-wall location and HP. This gets written before event data is read. So, I threw in the ability to reassign snag/cracked-wall HP so they all don’t have to be the same.

I’m going to see if I can add the wall spear trap. I will probably just copy the routine list from instant-fire and swap out the animation routine. This means the trap would do 10 fixed damage instead of that 10-defense thing, but I consider this an improvement. Plus, this way might allow me to implement it without needing to go into free space (thanks to the space I opened up earlier)


#17

What a boss.

As in put make a patch of the map visible in fog of war without units? That’s pretty nifty.


#18

Yeah, but the vision range decreases by 1 each turn.
At 02C266 if you change 01 to 00, the vision range won’t decrease but it also affects how the Torch staff operates.


#19

Oh, if it matters, it looks like the wall spear graphics are in FE8 too. (I was scrolling through GBAGE for fun, wasn’t on a road trip this time…)

EDIT: wait, wtf, why does FE8 have an image of FE6’s boxart in it

Caer Pelyn was gonna be in the opening maybe? also, mystery island?


#20

must be a leftover from fe7’s fe6 data transfer screen; looks like its connecting header graphic is in here as well. leaving chunks of the old game behind seems to be a recurring theme with the gba games; as i recall, they actually left fe6’s entire logo in fe7

(oh, and incidentally, here have the jp counterpart to the caer pelyn graphic)