Death Rally savegame modification

04 October 2010 22:20

Back in the days when Death Rally was new I played the shareware version a lot. Eventually, after finishing the game with a Sentinel, I wanted more and started exploring the game files using an HEX-editor but didn't really succeed. Now, more than 10 years after, I'm still interested in modifying the game files and after seeing Doomfrost's savegame mod I know it can be done.

What am I trying to accomplish?

Trying to understand how the savegames are build up and structured to modify game content.

Why is this difficult?

The savegames don't use plain text and every time you save, the encoding of the savegame will be different.

How did I start?

I run Death Rally using DOSBox and started a new game, didn't sign up for a race and saved the game on the first free savegame slot. This slot will generate file DR.SG0. I downloaded 'Hex Fiend' (HEX-editor for Mac OS, but there are many others out there) and opened the DR.SG0 savegame. Then I started editting the savegame in 8 byte blocks. This way I could notice differences in the game (including lock-ups when loading the savegame) and find out which line in the savegame is used for certain things like playernames and rankings.

After fiddling around with the values I discovered the location for Jane Honda's nickname. Because the savegame is encoded I can't just write a new name but change the hexadecimal value to something else and see what happens. Starting from this I changed every single hexadecimal value to see what would be changed. Due to this I reloaded the savegame a million times, looked at the score, players and their behavior during a game after changing one value. In case I noticed a change I tried to narrow down the change to a correct value which Death Rally understands and wrote it down.

What did I gain?

A table with locations (in bytes), hexadecimal values, binary values, area of effect and the effect. Unfortunately I'm not sure in which way the savegame is encoded but a few interesting bits and bytes are narrowed down to something useful. This includes the 'blocks' (each is 108 bytes) for each player within the savegame, some color variations, nick names and car types. This is the table for my DR.SG0 file:

Adr. Hex	Adr. Byte	Org. hex	New hex	Org. dec.	New dec.	Player	AoE	Difference
C0	192	33	?	51	?	2	Icon	?
C1	193	23	?	35	?	2	Icon	?
C2	194	65	?	101	?	2	Icon	?
C3	195	B7	A7	183	167	2	Score	87 to 215 points
C4	196	77	?	119	?	2	Score	?
C5	197	44	?	68	?	2	Score	?
C6	198	99	?	153	?	2	Score	?
C8	200	EE	FE	238	254	2	Ranking	2 to 16386
C9	201	99	?	153	?	2	Ranking	?
CA	202	DD	?	221	?	2	Ranking	?
EB	235	2C	34	44	52	3	Name	Jane Honda to Zane Honda
EC	236	18	19	24	25	3	Name	Jane Honda to Jene Honda
ED	237	CF	D0	207	208	3	Name	Jane Honda to Jave Honda
EE	238	68	69	104	105	3	Name	Jane Honda to Janu Honda
EF	239	93	94	147	148	3	Name	Jane Honda to Jane@Honda
F0	240	AB	AC	171	172	3	Name	Jane Honda to Jane Ionda
F1	241	E1	E2	225	226	3	Name	Jane Honda to Jane Hqnda
F2	242	F4	F5	244	245	3	Name	Jane Honda to Jane Horda
F3	243	5B	5C	91	92	3	Name	Jane Honda to Jane Honla
F4	244	8E	8F	142	143	3	Name	Jane Honda to Jane Hondq
118	280	B0	A8	176	168	3	Color	Grey (Greg Peck color)
118	280	B0	A9	176	169	3	Color	Black (Invalid?)
157	343	44	43	68	67	4	Name	Nasty Nick to Lasty Nick
173	371	D0	C0	200	192	4	Car	Wraith to Shrieker (Nasty Nick)
1DF	479	32	1A	50	26	5	Car	Wraith to Dervish (Motor Mary)
24B	587	93	7B	147	123	6	Car	Wraith to Dervish (Mad Mac)
2B7	702	F4	DC	244	220	7	Car	Wraith to Dervish (Matt Miler)
323	803	4E	36	78	54	8	Car	Wraith to Vagabond (Clint West)
38F	911	AF	B7	175	183	9	Car	Shrieker to Wraith (Lee Vice)
4D3	1235	C3	CB	195	203	12	Car	Sentinel to Shrieker (Iron John)
5AB	1451	86	8E	135	142	14	Car	Sentinel to Shrieker (Mori Sato)
683	1667	39	41	57	65	16	Car	Dervish to Sentinel (Diesel Joe)
6EF	1775	9A	92	154	146	17	Car	Dervish to Vagabond (Liz Arden)
75B	1883	F3	FB	243	251	18	Car	Vagabond to Dervish (Bogus Bill)
7C7	1986	55	5D	85	93	19	Car	Vagabond to Dervish (Farmer Ted)
7D8	2008	BC	B4	188	180	19	Color	Mint darkblue
7D8	2008	BC	C4	188	196	19	Color	Dark green
82A	2090	4F	4E	79	78	20	Upgrade	Engine (error, car can't move)
82A	2090	4F	6F	79	111	20	Upgrade	No steering, one engine == strafing
82B	2091	C9	CA	201	202	20	Upgrade	Tires -1?
82B	2091	C9	CC	201	204	20	Upgrade	Tires full (buggy)
82E	2094	81	7A	129	122	20	Upgrade	Tires (error, but works)
82F	2095	49	59	73	89	20	Upgrade	Armor (Sold out, error, works)
832	2098	5C	4C	92	76	20	Upgrade	Armor (0%, works, perhaps weaker)
833	2099	B6	BE	182	190	20	Car	Vagabond to Dervish (Maxi Cosi; player)
843	2115	40	81	64	129	20	Color	Yellow
844	2116	7F	79	127	121	20	Color	Dark green
844	2116	7F	6A	127	106	20	Color	Blue (Bogus Bill grey selectable)
847	2119	8C	9C	140	156	20	Money	From 495 to 271
850	2128	2C	?	44	?	20	Icon	?
85B	2139	CF	DF	207	223	20	Score	From 0 to 128
860	2143	6B	6C	107	108	20	Ranking	From 20 to 22
864	2148	17	18	23	24	20	Races won	From 0 to 256
867	2151	69	70	105	112	20	Total races	From 1 to 57
870	2160	E3	E2	227	226	20	Total income	From 0 to 65280
873	2163	C2	C3	194	195	20	Market	Mines active and bought
87B	2171	F4	F5	244	245	20	Market	Turbo boost active, but not bought

Racing against Mori Sato in a Shrieker and Diesel Joe in a Sentinel.

Do it yourself

Remember: each time you save the game the values will be different. This means that my table can't be applied onto your savegame. If you want my original savegame you can download it here: DR.SG0. You can download my slightly modified savegame in chapter 'Done it myself'. Also note that HEX-editors can vary a bit so get to know your version of your HEX-editor.

1. Download Hex Fiend (Mac OS X) or XVI32 (Windows);
2. Create a back-up of your savegame;
3. Open the savegame with your HEX-editor;
4. Go to position/byte 1986 or 0x7C7 (for player 19's car) and read the hexadecimal value (i.e. 55)(click for example);
5. Recalculate the hexadecimal value to binary (=85) and add up 8 to go from Vagabond to Dervish;
6. Revert the binary value (85+8=93) back to hexadecimal (=5D);
7. Replace the original hexadecimal value with the new one and save your file;
8. Make sure that the new file is in the root of the Death Rally directory (where is originally was);
9. Load up your game, start a race and hope that player 19 will participate.

Using my DR.SG0 file along with the example above will change Farmer Ted's Vagabond to a Dervish. As you can see there is a pattern in hexadecimal values and if you're familiar with it you won't have to use the hexidecimal/binary converter. Of course you can always try to "just fill something in and see what happens" but this is most likely to fail. Especially with the cars because these values have to be exact (with color, money, nicknames you have more 'freedom').

The trick is to find what everything means. I noticed that the savegame works in blocks of 108 bytes. See the table for example; 371 and 479 change cars for respectively player 4 and 5. This means that 479 + 108 (= 587) will change the car of player 6. Unfortunately this system is not 100% correct as there is just 103 between player 18 and 19.

Remember the following facts when changing values:
- Car values are exact. Increase the binary value by 8 to get a faster car, decrease by 8 for a slower car (Starting from Vagabond and up to Deliverator).
- Be careful when defining to much cars of the same type. You need enough cars to fill up one type of race (i.e. Easy, Normal and Hard Races) otherwise Death Rally will crash. This means it's safe to give Farmer Ted a Dervish (he can participate in Easy and Normal race) but it's dangerous to give all the Deliverator and Wraith racers a Dervish because there aren't enough players left over for the Hard Race. One more thing: you need more than 4 cars that can race with the Hard Race because sometimes a player is not selected for participation. It's safer to have at least 6 players that can participate in each type of race.
- Money and color is defined by up to 3 locations in the file. For instance byte 192, 193 and 194 are used to define the colors for player 2 and you can de/increase 192 by some value but can't do so with 193 and 194. You'll need a different one.
- There are 'weird' values like refund-value of your car. I haven't located them yet and are only interesting to fill out the gaps in the savegame. Especially for AI players because they don't care about money.

Done it myself

In case you don't want to edit yourself but just want to see a slight different game, then see this DR.SG1 (based on my DR.SG0) for a modified game. It has:
- Different player colors selectable;
- Farmer Ted's car is darker;
- Bogus Bill upgraded to Dervish;
- Diesel Joe upgraded to Sentinel;
- Iron John upgraded to Shrieker;
- Mad Mac upgraded to Deliverator.

Some images

Modified players, ain't it nice to see a silver Dervish?

I would really be interested in seeing this go further. I always wanted different colors for my cars, as the player selection and naming system are very good already. Let me know if you've uncovered anything new!!

A while ago I was thinking about diving deeper into this. I'm not sure if I can discover the encryption method of the savegame (although I know it involves date/time as a variable). It would be nice to create a program that can modify settings. If I have more information I'll post it .

I decompiled de original Death rally(because i'm making a open source implementation) and i know how to decrypt/crypt the savegame files. Now you can edit your favourite savegame and give you more money or change your car....

I publish on my github account:
https://github.com/enriquesomolinos/DreeRally/tree/master/tools

If your like this tools please, star my repo.

Interesting and great work!

Interesting stuff, I am the guy that helped Doomfrost spread his mod on the internet, back in the day.

I am trying to get the Adversary's car, but it looks like it's not an easy feat. I remember someone managed to did that back in the day, even though car controls were bugged.

Did you manage to get that car with the hex editor?

Wait man.. I actually have it, I really didn't remember I did lol. Really unbelievable... And it's a savegame for the shareware version too! You can download it from here:

http://www.rapidshare.com.cn/obOeqQV

I didn't get the Adversary's car using a hex editor. Cool that you've managed to get it! Can you upload the file again? The uploadlink has expired.

I just wish I could find a way to get the all of the tracks to not be limited to just Easy Medium Hard. All I can basically do for right now is reorder the track listings in a memory editor. Which has made maps like Suburbia show up in Hard listing.

Sounds interesting! Can you shed light some extra light on the way you reorder the tracks using a memory editor? I'd like to know more about that subject .

Guys...someone needs to create a game editor for death rally...PLEASE one of you geniuses out there do it. I love death rally and wish it had different starts every time i load it. Player rankings, cars they start with, etc...it would be REALLY cool if people upgraded their cars on wins too. But for now keep it simple.

you can edit your savegames following tye steps described in my repository

https://github.com/enriquesomolinos/DreeRally/tree/master/tools

Yeah but I don't know anything about Python or how to run those files at github. Can someone simplify an editor for stupid people like me?

wrote on 10 December 2017 21:02:
you can edit your savegames following tye steps described in my repository

https://github.com/enriquesomolinos/DreeRally/tree/master/tools

Thanks to Enrique's project (and tools), and to this article I've done a little savegame editor (Italian and English Version).

Usage: copy file into DR folder and launch it.

Known bugs: for certain values of key byte (maybe less than 64?), savegame loads odd values. Try to save game from DR again and reload file into editor.

Remarks and considerations :

- if you assign a Vagabond to all drivers, you can have fun things such as, for example, Bogus Bill, Cher Stone and Duke Nukem in the same Hard Race.

- Mines value: to my surprise

this value isn't yes/no, but the number of mines available in race. I've tried with 16 and yes, I've managed to use 16 mines in race! (they are also visible on screen!)

Edit: Screenshot

Italian Version :

https://sport.advancedstudios.it/client/DR_editor/DR_Editor_ITA.jar

English Version :

https://sport.advancedstudios.it/client/DR_editor/DR_Editor.jar

This reply has been editted 1 time.

Great work!,

Can I publish your util in my page www.dreerally.com?

Thank you very much!

Yes, of course you can.

Also, thank you again for your tools and project.

Great work guys!

Nice stuff! I've reuploaded the savegame featuring the Adversary's car:

https://www.mediafire.com/file/bacokiwczwddwcd/DR.sw6

Hello to all!

I've downloaded your savegame, but the size isn't 2179 bytes, so loading it in the game doesn't work.

Meanwhile ...

(sorry for the image size )

Result obtained by inserting the files of the "file 1" in the archive "file 0" (keeping the names) and adding bytes to respect the size of the original BPA

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The DR.SW6 savegame is for the shareware version of Death Rally. Great work getting the Adversary's car in that version! Never thought that the Adversary's car would steer that bad! But it's fast and tough, however .

I fixed your image by the way, Simo .

Mirror of the DR.SW6 file: DR.SW6.

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Thanks for both then

I didn't remember that the file sizes were different from shareware to full version

The Adversary's car lasts only one race, but great work anyway!

Great work guys!!

I publish on my website a f1 2018 mod savegame for death rally. I hope you enjoy it!

http://www.dreerally.com/f1-2018-savegame-mod-for-death-rally/

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Hi Enrique! Good work!

(I can't comment on your site at the moment)

Below I write a consideration about your mod, that can be useful also in this topic.

Quote: "Driver face image can be repeated because at this moment we canâ€™t change the faces to substitute with the real faces."

Maybe yes, they could be changed. I'm testing your bpk file algorithm from tools (I'm looking at the BPK algorithm for track BPAs), but in addition to the wrong palette, I can only decrypt part of the image (the first GIF block I think). However, in DreeRally the images are seen well, so you should have the updated and correct algorithm (in your dr.c source seems a LZW/GIF decompression with modified palette). The idea would be to extract BPK from the BPA, convert it into a gif image, modify it, reconvert it into BPK and store it again in the BPA, keeping the size of the entire BPA file unchanged.

Sorry for the Anonymous mistake the message above is mine.

Hi,

Firstable, comments have been fixed in my blog now thanks.

About the BKP files we have a problem. I know that the palette is worng in my tool but if you want to put a custom image in Death Rally probably you need to change the palette, and as far as I know the Death Rally palettes are used too much. When I decompile I see that the same palette (256 colours) is used for faces, cars, menus and more, so I think it's difficult to change bkp files correctly.

You are welcome

Yes, but it's also true that if you launch your DreeRally executable, the images are shown correctly as stated also in the screenshot of your project . So you have, even if "indirectly", a functional BPK decode algorithm for entire images. In other words, you can decode an image with its correct "shape" only with wrong colors.

(It's not your fault, palettes and/or BPKs should be bit rotated)

All this if I'm not mistaken, of course

Can these considerations described at this external link be useful to you?

http://forum.xentax.com/viewtopic.php?f=18&t=3601

I'm trying also an "inverse deduction" : if you take a screenshot from the game and cut out pixels of sprite for example for Sam Speed face, then save it in BMP format so you have the correct solution of which color should result in that particular pixel, and from here, BPK file and PAL file, deduce correct bit transformation.

Hi to all,

As we know, in the shareware version we can use the adversary's car for one race, and now we can do this in the full version!. After decompilation and tests time I publish the savegame to do this:

http://www.dreerally.com/do-you-want-to-play-a-race-with-the-adversary-car/

I hope you'll enjoy it

Excellent work! Can't wait 'till you publish the how-to next week .

In the past I've also seen a screenshot with a player against the Adversary in one of the regular maps. In other words: play the final round in any other map than the Arena. Would that be the next challenge to achieve in savegame modding?

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Hi,

This situation cannot be achieved with a savegame, we need to make a trainer or something like that to modifing the executable in run time.

See the updates in
http://www.dreerally.com/ because in few weeks you have great news about that!

Hi to all

After several tries, a small but maybe important mod in game.

follow updates on www.dreerally.com. A new death rally editor and launcher are released!

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