custom caves

It is usually more than modern vanilla. Many servers alter generation rules, cave themes, ore and structure placement, or mix procedural changes with hand-tuned areas. The defining trait is that underground gameplay is designed on purpose, not left to default generation.

Even small distribution changes can shift pacing. Some servers keep totals similar but move resources into pockets that require travel and risk, which slows early gearing. Others concentrate common ores to reduce grind while pushing high-tier materials deeper or into more dangerous routes.

Treat it like a navigation and recovery problem: plenty of light, bridging blocks, food, a water bucket, and spare tools. Inventory space matters because good finds can be sudden, and having a planned exit route is often safer than pushing one more branch.

A lot. In PvE, the tension comes from terrain, darkness, and sustained fights. With PvP enabled, junctions, resource rooms, and return paths become natural ambush zones, so securing entrances, controlling chokepoints, and traveling light can matter as much as raw mining efficiency.

Seed sharing is often less useful because generation is modified or partly bespoke. Maps still only show surface. Minimap usefulness depends on server rules, but vertical, layered cave networks tend to stay harder to fully read than flat terrain.