Inspiration
I have played Minecraft OneBlock maps and modpacks for a long time, but most eventually follow the same pattern: break one block, advance through a few fast phases, automate the available resources, and finish within one or two days.
The block may be infinite, but the experience around it usually is not.
I wanted to build a OneBlock project designed for long-term progression, customization, mod integration, multiplayer cooperation, and continued development beyond the starting island.
That became OneBlock-Z.
Build Week happening at the same time was a complete coincidence. I began the project two days after the event started without knowing it existed. Since GPT-5.6 and Codex were already central to the development process, I decided to submit what I had built.
What it does
OneBlock-Z is a Minecraft Forge 1.20.1 project built around one shared Infinite Block.
Every successful block break advances a world-wide progression counter, allowing every player in the world to contribute to the same progression. The current architecture supports nine functional phases followed by five Prestige tiers, with configurable thresholds and synchronized interface systems.
A permanent invisible support surface also prevents players from falling through the Infinite Block while it is temporarily absent during rapid replacement.
Phase HUD
The configurable Phase HUD displays:
- the current phase;
- total block progress;
- the next phase threshold;
- completion percentage;
- a progress bar.
It becomes fully visible when the Infinite Block is broken, then fades toward a configurable idle opacity. Players can change its position, size, opacity, progress colour, or disable it entirely.
Configurable ticker
OneBlock-Z includes a permanent scrolling information ticker rather than a fixed HUD bar.
Players can customize:
- movement speed;
- Smooth or deliberately Stepped motion;
- left-to-right or right-to-left direction;
- five text sizes;
- global colour;
- individual condition colours;
- enabled or disabled conditions;
- separator text and colour;
- spacing;
- pause and focus behaviour.
Fixed-width condition cells allow live values to update without making the entire ticker jump or change spacing.
Virtual Field Guide
The /ob guide command opens a completely virtual Field Guide without placing a physical item into the player’s inventory.
The guide contains thirteen chapters covering progression, commands, the Jackpot, dimensions, safety, void recovery, interface settings, Wood Exchange, future content, and credits.
It includes clickable chapter and page navigation, direct chapter aliases, first-join reminders, and an interactive void-loss calculator.
Jackpot
Every eligible Infinite Block break has a very small chance to trigger the Jackpot.
When a Jackpot occurs:
- the winner receives a five-second animated
JACKPOT!display; - a private clickable message allows the reward to be claimed;
- other players receive a public winner announcement;
- rewards remain queued if multiple Jackpots are won before claiming;
- the reward screen provides two different enchanted books;
- enchantments can reach twice their normal maximum level.
Wood Exchange
The Infinite Block intentionally provides ordinary oak logs rather than flooding progression with every possible wood type.
Players can instead hold a stack of eligible logs and use /ob exchange wood to convert the entire stack into another safe cosmetic wood type at a one-to-one ratio.
The system supports approved vanilla and modded logs while excluding special wood types that could provide unintended mechanical advantages.
Void recovery
Void deaths use a custom recovery system inside OneBlock-Z dimensions.
For ordinary item stacks, one third of each stack is preserved. Damageable equipment survives but returns with no more than one third of its durability.
Recovery data is persisted and restored exactly once, while worlds using keepInventory bypass the custom penalty.
Nightmare mode
OneBlock-Z includes a separate Nightmare world option during world creation.
Nightmare uses Survival gameplay with:
- Hardcore behaviour;
- locked Hard difficulty;
- cheats disabled;
- a persistent world-level Nightmare flag;
- doubled final incoming player damage.
The same world flag also provides the foundation for future Nightmare-specific end-game mechanics.
Custom Nether
Normal obsidian Nether portals lead to a custom Nether environment.
Portals support:
- ignition with flint and steel or fire charges;
- travel from the OneBlock world to the custom Nether;
- safe return travel;
- normal 8:1 coordinate scaling;
- destination portal reuse or safe creation.
How I built it
I designed the progression rules, mechanics, interface behaviour, visual language, edge cases, balancing logic, and player experience.
GPT-5.6 helped convert those ideas into detailed implementation specifications, identify contradictions, reason through edge cases, and divide the project into manageable development milestones.
Codex worked directly inside the Forge repository. It implemented isolated systems, added networking and persistence, created migrations, fixed runtime failures, and produced detailed reports describing changed files and known limitations.
I manually launched the mod, tested every interface and mechanic inside Minecraft, identified incorrect assumptions or visual problems, and provided precise corrections until the behaviour matched the intended design.
The repository now contains more than 350 automated tests, alongside repeated in-game visual and runtime testing.
Challenges
The largest challenge was translating a very large creative design into safe, isolated Forge systems.
Features could compile and pass automated tests while still behaving incorrectly inside Minecraft. Interface spacing, rendering scale, world creation hooks, mod compatibility, resource paths, menu behaviour, networking, and persistence all required real runtime testing.
For example, one world-creation implementation caused a mixin crash and had to be replaced with a safer Forge event. A Mekanism recipe also referenced an empty Venus sandstone tag, requiring a compatibility fix through KubeJS.
The ticker and Field Guide required repeated visual feedback because technically correct rendering was not always readable or pleasant at different GUI scales.
This taught me that automated testing is essential, but it cannot replace direct visual inspection and gameplay testing.
What I learned
I learned how to turn a large design into smaller technical milestones, write clearer implementation specifications, inspect Git changes and build reports, test multiplayer-safe state, and distinguish code that merely compiles from a feature that actually feels correct in-game.
Most importantly, I learned that AI-assisted development still requires strong human direction.
GPT-5.6 and Codex accelerated implementation enormously, but they did not decide what OneBlock-Z should become. The design, priorities, testing, rejection of incorrect results, and final judgement remained my responsibility.
Future development
The current submission is a working foundation rather than the final planned experience.
Future development includes:
- completing and balancing the full progression content;
- expanding optional mod integrations;
- further visual polish;
- a custom End dimension called The Roots;
- the Crown and Rootheart systems;
- the final Root-Defender encounter;
- resurrection and advanced Nightmare progression;
- additional multiplayer rewards and long-term end-game content.
OneBlock-Z began as an attempt to improve a repetitive OneBlock formula. It has grown into the foundation of a configurable, long-term progression world.
Making Mods We Actually Want to Use.
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