Clean-Room Legal Roadmap
This record is part of the red-team investigation archive. It records
investigator-side observations and evidence for later green-team
filtration into implementation-neutral specifications; it is not
blue-team implementation material.
Date: 2026-05-18.
This record states known facts, open gaps, and project rules for a
future clean-room reimplementation. It is not legal advice.
The governing focus is United States and Australian law. The project
is not being undertaken in Europe. The EU decompilation regime is
included only as a comparison.
Current Project
Classification
Known facts:
- This repository contains red-team investigation work.
- The investigation has used a lawfully held copy of Zoo Tycoon
2.
- Investigators have run the game under Wine.
- Investigators have inspected memory, disassembled executable images,
decompiled runtime images, named functions and data, carved executable
material, patched local experimental binaries, and studied the
wrapper/protection boundary.
- The repository contains records, analysis scripts, symbol/name
ledgers, wrapper notes, SecServ trampoline evidence, and local
experimental artifacts.
Classification:
- This repository is the red-team investigation database.
- It is not the future blue-team implementation repository.
- Records in this repository may contain facts that can be filtered
into a green-team specification.
- Records in this repository are not automatically blue-team material
because many of them were written from direct binary inspection.
Project rules:
- Before publishing red-team investigation material, verify clean
boundaries.
- Do not publish original files, carved executables, patched binaries,
memory dumps containing original code, SecServ bypasses, wrapper
bypasses, or asset archives.
- Present red-team findings to a green/spec team for filtration.
- Give blue-team implementers only green-team specifications.
- Require users to supply their own legally obtained game files and
assets.
- Use Zoo Tycoon, Microsoft, Blue Fang, SafeDisc, C-Dilla,
Macrovision, Rovi, TiVo, and Xperi names only for factual or nominative
reference.
- Do not use those names, logos, title art, screenshots, or trade
dress as project branding.
- Treat copyright, anti-circumvention, patent, and trademark questions
as separate questions.
Current Effort To Date
The project has produced or used:
- runtime memory dumps and Wine execution logs;
- Ghidra/Rizin analysis of executable images;
- symbol/name ledgers, including hundreds of function names and many
data labels;
- wrapper-boundary analysis of SecServ trampolines and runtime slot
tables;
- carved or patched executable artifacts for local
experimentation;
- asset and XML investigations used to infer domain schemas and game
semantics;
- records describing the known binary layout, resource inventory,
wrapper layout, SecServ
.txt transform, and unresolved
regions.
This is red-team reverse engineering for understanding,
interoperability, and possible future reimplementation.
This repository is not a distributable replacement engine.
United States Law
Known authorities:
- Sega v. Accolade: the Ninth Circuit treated disassembly as fair use
where it was needed to inspect unprotected ideas and functional concepts
for a legitimate compatibility purpose.
- Sony v. Connectix: the Ninth Circuit held that intermediate copying
of the PlayStation BIOS during development of a compatible emulator
could be fair use.
- Atari v. Nintendo: the Federal Circuit recognized that reverse
engineering object code in lawfully possessed chips could be legitimate;
Atari's use of a source-code copy obtained from the Copyright Office
under false pretenses created a provenance problem.
- Computer Associates v. Altai: software infringement analysis filters
out ideas, processes, facts, public-domain material, efficiency
constraints, external constraints, and standard techniques before
comparing protected expression.
- Google v. Oracle: reuse of software interface material for a new
compatible program can be fair use in context; that case does not
authorize wholesale copying of implementation code.
Rules derived for this project:
- Red-team work may document facts, behavior, file formats, schemas,
interoperability boundaries, and runtime interfaces.
- Green-team specifications may use filtered factual material.
- Blue-team code must not copy original source, decompiled pseudocode,
instruction sequences, recovered function bodies, or expressive game
content.
- Provenance records matter. Keep red, green, and blue materials
separated.
DMCA Section 1201
Known rule:
17 U.S.C. § 1201(f) permits a person who has lawfully obtained the
right to use a copy of a computer program to circumvent access controls
for the sole purpose of identifying and analyzing elements necessary to
achieve interoperability of an independently created program, when those
elements are not otherwise readily available. It also permits necessary
means and limited sharing for interoperability, subject to the statutory
conditions.
Project rules:
- Wrapper/protection analysis must remain tied to interoperability of
an independently created program.
- Do not publish a crack, patched original game executable, wrapper
bypass, game asset archive, or general-purpose circumvention
package.
- Do not distribute SecServ or SafeDisc code or binaries.
Australian Law
Known provisions:
- Copyright Act 1968 (Cth) section 21 treats deriving source code from
object code by decompilation as a reproduction of the program.
- Section 47D permits reproduction or adaptation by or for the owner
or licensee of a copy where it is for obtaining information necessary to
make an independent program or article interoperate with the original
program or another program, only to the extent reasonably necessary, and
only where the information is not readily available elsewhere.
- Sections 47E and related provisions address error correction and
other limited computer-program purposes.
- Section 47G can remove the benefit of the exception if copies or
information made under those provisions are later used or supplied for
another purpose.
- Australia also has anti-circumvention provisions with
interoperability exceptions for access-control technological protection
measures, subject to statutory conditions.
- Stevens v. Sony construed an earlier TPM definition narrowly in the
PlayStation mod-chip context. It is not a current general rule
permitting game-protection bypasses.
Project rules:
- Keep Australian-facing reverse-engineering work tied to
independent-program interoperability.
- Do not distribute original code, copied assets, patched executables,
memory dumps, carved binaries, or general-purpose circumvention
tooling.
- Do not reuse information obtained for interoperability for unrelated
purposes.
EU Comparison
Known rule:
Directive 2009/24/EC, Article 6 addresses decompilation for
interoperability where reproduction or translation of code is
indispensable to obtain necessary interoperability information, subject
to conditions.
Project fact:
- The project is not being undertaken in Europe.
Use in this record:
- The EU rule is a comparison point only.
- It illustrates the same operational boundary used here: decompile
only for necessary interoperability information, do not use the
information for unrelated purposes, and do not copy protected expression
into the independent program.
Comparable Projects
Known facts:
- OpenMW is a replacement engine for Morrowind. It does not ship the
original proprietary Morrowind content; users supply their own game
data.
- OpenRCT2 is an open-source reimplementation of RollerCoaster Tycoon
2. Its documentation states that original RCT2 files are required to
play.
- OpenGOAL is a decompilation/recompilation project for Jak and
Daxter's GOAL code. It openly describes recovering source-like GOAL code
from the original game.
Project rule:
- The public-distribution model for a future blue-team project is
replacement engine plus user-supplied assets, not distribution of
original executable code, original assets, carved binaries, or patched
binaries.
Copyright Boundaries
Known rules:
- Facts, ideas, systems, procedures, file-format facts, protocol
behavior, observed input/output behavior, and functional requirements
are not the same as copyrightable implementation expression.
- Original implementation code, source-like decompiled structure,
expressive text, art, audio, video, missions, scenarios, and asset
content are copyright material unless another legal basis applies.
Green-team material may include:
- asset container structure;
- XML schemas and field names present in user-supplied data;
- file-format records and value ranges;
- observed UI/gameplay behavior;
- black-box input/output behavior;
- high-level state machines;
- compatibility requirements.
Green-team material must exclude:
- original source or decompiled pseudocode;
- function bodies or instruction sequences;
- exact recovered control flow;
- copied implementation constants, tables, or data layouts unless they
are functional facts needed for interoperability and are documented as
such;
- inferred original source-tree or module structure;
- patched or carved executable bytes;
- wrapper-bypass methods;
- expressive game text, art, audio, missions, scenarios, or UI layouts
except as references to user-supplied assets.
Blue-team code must be written from filtered specifications, public
facts, independently authored tests, and user-supplied assets.
Trademark Boundaries
Known marks and trade identifiers include:
- Zoo Tycoon;
- Zoo Tycoon 2;
- Microsoft;
- Blue Fang;
- SafeDisc;
- C-Dilla;
- Macrovision;
- Rovi;
- TiVo;
- Xperi;
- associated logos, title art, and trade dress.
Project rules:
- Do not use those names as project names, logos, or branding.
- Use nominative wording only where needed to describe compatibility,
for example "compatible with user-supplied Zoo Tycoon 2 game
files".
- Do not imply sponsorship, endorsement, or official status.
- Do not ship screenshots, logos, title art, or game UI assets as
promotional material unless a separate legal basis is identified.
Patent Boundaries
Known rules:
- Copyright cleanliness does not answer patent questions.
- Patents protect claimed methods, systems, and apparatus.
- A separately written implementation can still infringe an unexpired
patent if it practices the claimed invention.
Known project facts:
- Zoo Tycoon 2 is old enough that many patents relevant to the
original product may have expired.
- Expiration cannot be assumed for every potentially relevant
patent.
- A public release plan needs a targeted patent search for the
mechanisms the replacement engine intentionally implements.
Project rule:
- Before public release, perform a targeted patent search covering
game-simulation, UI, asset-streaming, pathfinding, and
protection-wrapper mechanisms that the project intentionally implements
or replaces.
SafeDisc Originators
And Rights To Observe
Known facts:
- The protection wrapper is a separate legal object from the Zoo
Tycoon 2 game logic and assets.
- SafeDisc began as C-Dilla/Macrovision technology.
- Macrovision and C-Dilla jointly developed and marketed SafeDisc in
the late 1990s.
- C-Dilla was acquired by Macrovision in 1999.
- Macrovision later became Rovi, then TiVo Corporation, then merged
into the Xperi corporate chain.
- Macrovision sold substantially all Trymedia assets to RealNetworks
in 2008.
- SafeDisc operations ended around 2009.
Known gap:
- The present copyright owner of particular SafeDisc program code has
not been established from the public sources reviewed here. Depending on
asset-transfer documents, ownership may sit in the Xperi/Rovi line, the
RealNetworks/Trymedia line, or another successor/assignee.
Patent facts:
- SafeDisc had patent coverage.
- The clearest public SafeDisc-linked patent is U.S. Patent 6,353,890,
"Method for copy protecting a record carrier, copy protected record
carrier and means for detecting access control information."
- The patent record lists Peter A. Newman as inventor, C-Dilla Ltd as
original assignee, later Macrovision/Rovi assignments, and a current
listed Rovi-family assignee.
- The patent is listed as expired for lifetime, with an anticipated
expiration date of 29 May 2018.
- A 2002 Macrovision announcement described that patent as fundamental
to SafeDisc and SafeAuthenticate.
Trademark fact:
- The U.S. SAFEDISC trademark registration appears dead/cancelled for
failure to file continued-use paperwork in 2011.
Rules:
- Do not distribute SafeDisc, SecServ, C-Dilla, or related wrapper
code.
- Do not distribute carved DLLs, patched binaries, runtime dumps,
bypasses, or replacement components derived from protected wrapper
implementation code.
- Red-team records may document that SafeDisc/SecServ/C-Dilla wrapper
material was observed.
- Green-team specifications treat wrapper behavior as an
interoperability boundary.
- Blue-team work must not include copied SecServ logic, copied wrapper
tables, SafeDisc-compatible circumvention code, or binaries derived from
the original wrapper.
- Patent expiration for U.S. Patent 6,353,890 does not make SafeDisc
software implementation code public domain.
- The dead/cancelled SAFEDISC trademark record does not answer
copyright or anti-circumvention questions.
Red, Green, And Blue Roles
Definitions:
- Red team: anyone or any agent that has seen the original executable,
disassembly, decompiler output, memory dumps, carved binaries, patched
binaries, wrapper traces, SecServ trampoline ledgers, or other raw
reverse-engineering evidence.
- Green/spec team: a non-implementation review function that may read
red-team records and findings solely to filter them into factual,
implementation-neutral specifications.
- Blue team: anyone or any agent writing a replacement engine or
reusable public tooling from filtered specifications only, without
access to original code, decompiler output, dumps, carved binaries, or
red-team implementation notes.
Operational rules:
- Green-team exposure to red-team findings is for filtration
only.
- Green-team specifications are blue-side inputs only after
code-shaped detail and expressive material are removed.
- The green team does not inspect original binaries, traces, dumps,
disassembly, decompiler output, carved binaries, or patched binaries
directly.
- If a human or agent has worked in the red repository on a subsystem,
classify that human or agent as red for that subsystem.
- A red participant does not later implement the same subsystem on the
blue side from memory and call it clean.
- Blue agents start from a clean context.
- Blue agents receive only filtered specification files.
- Blue work happens in a separate repository.
- Prompts, inputs, outputs, and review decisions are preserved as
clean-room logs.
- Blue patches that reproduce red-side code structure without an
independent functional reason are rejected.
Roadmap
Milestone
1: Freeze And Label The Red Investigation Database
Rules:
- Verify clean boundaries before publishing red investigation
material.
- Label analysis documents by role:
- red-team binary analysis;
- factual interface/specification;
- blue-team implementation;
- user-supplied original asset requirement.
- Do not publish carved executables, patched binaries, memory dumps
containing original code, asset archives, wrapper bypasses, or
decompiler output.
Milestone 2: Produce
Filtered Specifications
For each subsystem, write a filtered specification containing:
- file formats and schemas;
- field names and types inferred from assets;
- state machines and behavior tables;
- public or user-visible mechanics;
- black-box test cases;
- compatibility requirements;
- error handling and edge cases observed through execution.
Do not include:
- decompiled pseudocode;
- instruction listings except small addresses used as evidence
references;
- original function body structure;
- copied strings unless they are required identifiers from
user-supplied data;
- proprietary assets or expressive text.
Milestone 3: Build A Replacement
Engine
Rules:
- Create a separate blue-team repository.
- Use a different programming language from the original Windows x86
executable.
- Use a different software architecture and module layout.
- Target a different instruction/machine architecture.
- Do not use recovered function order as an architectural guide.
- Do not directly translate decompiled routines.
- Do not compile, link, embed, patch, or load original executable
code.
- Implement against user-supplied assets, XML/Z2F schemas, black-box
behavior tests, public gameplay facts, and filtered specifications.
Milestone 4: Compatibility
And Distribution
Distributable artifacts may contain:
- original replacement engine source;
- independently authored tools;
- schema descriptions;
- test fixtures that do not contain copyrighted game content;
- scripts that locate user-owned game files without copying them into
the repo.
Distributable artifacts must not contain:
- Zoo Tycoon 2 executables or DLLs;
- SecServ or wrapper bypass code designed to run the original binary
without authorization;
- packed assets, music, videos, models, textures, campaigns, or
scenarios from the game;
- memory dumps or carved binaries;
- trademarked logos or title art.
Milestone 5: Release Checklist
Before public release:
- audit the repository for copied strings, assets, binaries, dumps,
and decompiler output;
- document that users need a legally obtained copy of the game;
- add a trademark disclaimer;
- add a contributor certificate requiring original contributions and
no copied proprietary code;
- preserve clean-room review logs;
- complete the targeted patent search;
- have counsel review the release package.
Source Notes
- 17 U.S.C. § 1201(f), reverse-engineering interoperability exception:
https://www.law.cornell.edu/uscode/text/17/1201
- Sega Enterprises Ltd. v. Accolade, Inc., 977 F.2d 1510: https://www.bitlaw.com/source/cases/copyright/Sega-Accolade.html
- Sony Computer Entertainment, Inc. v. Connectix Corp., 203 F.3d 596:
https://caselaw.findlaw.com/court/us-9th-circuit/1452245.html
- Atari Games Corp. v. Nintendo of America Inc., 975 F.2d 832: https://law.justia.com/cases/federal/appellate-courts/F2/975/832/163650/
- Computer Associates International, Inc. v. Altai, Inc.: https://www.bitlaw.com/source/cases/copyright/altai.html
- Google LLC v. Oracle America, Inc.: https://www.law.cornell.edu/supct/cert/18-956
- Australia Copyright Act 1968, including sections 21, 47D, 47E, 47G
and TPM interoperability provisions: https://www.legislation.gov.au/C1968A00063/2024-03-20/2024-03-20/text/original/epub/OEBPS/document_1/document_1.html
- Stevens v. Kabushiki Kaisha Sony Computer Entertainment: https://www.hcourt.gov.au/cases-and-judgments/judgments/judgments-1998-current/stevens-v-kabushiki-kaisha-sony-computer-entertainment
- Directive 2009/24/EC, Article 6 decompilation comparison: https://eur-lex.europa.eu/eli/dir/2009/24/oj
- OpenMW FAQ: https://openmw.org/faq/
- OpenRCT2 repository documentation: https://github.com/OpenRCT2/OpenRCT2
- OpenGOAL FAQ: https://opengoal.dev/docs/faq/
- SafeDisc patent, U.S. Patent 6,353,890: https://patents.google.com/patent/US6353890B1/en
- Macrovision announcement describing U.S. Patent 6,353,890 as
fundamental to SafeDisc and SafeAuthenticate: https://www.cdrinfo.com/d7/content/macrovision-awarded-cd-copy-protection-patent
- RealNetworks acquisition of substantially all Trymedia assets from
Macrovision: https://realnetworks.com/press/releases/2008/realnetworks-acquire-trymedia-macrovision
- Rovi completion of TiVo acquisition and TiVo rebrand: https://investor.xperi.com/news/news-details/2016/Rovi-Completes-Acquisition-of-TiVo-New-TiVo-Poised-to-Lead-Media-and-Entertainment-Transformation/default.aspx
- SafeDisc trademark status record: https://www.trademarkelite.com/trademark/trademark-detail/75480951/SAFEDISC