Dome Keeper Drillbert Upgrade Priority and Build Guide

To maximize Drillbert's efficiency in Dome Keeper, prioritize drill hardness upgrades over duplicate companions or automation gadgets. Subterranean rock transitions from soft topsoil into dense stone and bedrock as you dig deeper. If Drillbert lacks the strength to pierce the current rock tier, he stalls or falls asleep immediately, making additional companions useless until his drill is upgraded.

Drillbert Upgrade Order and Resource Investment

Drillbert carves horizontal two-tile-high passages automatically, freeing you to dig the central vertical shaft, scout relic chambers, and ferry ore to the dome. However, an unupgraded Drillbert requires constant manual nudging to stay awake and cannot break tougher rock strata. Upgrade his hardness as soon as your main vertical shaft reaches second-tier rock.

Purchasing companion eggs or feeding gadgets before securing adequate drill strength creates an expensive bottleneck. Always ensure your companions can break the rock density of your current working depth before investing in support tools.

Deploying Drillberta and the Treat Dispenser

Once Drillbert's hardness matches the depth of your shaft, unlock the Drillberta egg and the Treat Dispenser to turn manual excavation into an autonomous mining system.

1. Establish a central drop shaft: Dig your primary vertical route past the targeted resource stratum before deploying companions horizontally.
2. Assign split-lane mining routes: Place Drillbert into the left wall and Drillberta into the right wall at the same vertical depth. This dual-direction setup clears an entire horizontal layer simultaneously, uncovering hidden deposits of Iron, Cobalt, and Water.
3. Automate companion stamina: Install the Treat Dispenser to feed both units automatically. Because active digging rapidly drains companion stamina, the dispenser keeps both Drillberts working and provides temporary drilling speed boosts without requiring you to travel down and nudge them awake.

Solving the Hauling Bottleneck

Drillbert fractures rock blocks but cannot transport resources. High-speed horizontal excavation leaves large piles of loose ore scattered along deep tunnels. Uncollected ore provides no defensive value while alien waves scale in strength.

To prevent logistical delays, establish centralized staging zones:

• Let your companions dig long stretches without following directly behind them to grab individual minerals.
• Sweep completed tunnels periodically, pulling loose iron and water to the intersection where the lateral corridor meets your main drop shaft.
• Haul concentrated resource bundles up the vertical shaft in single batches, upgrading your keeper's carry capacity and engine speed to match the increased volume of loose ore.

Balancing Iron Between Mining and Dome Defense

Maxing Drillbert requires significant Iron, and the Treat Dispenser demands Water that could otherwise support dome systems. Spending all early resources on mining upgrades leaves the dome vulnerable to fast aerial spitters, armored walkers, and dive bombers during Relic Hunt runs.

Maintain an alternating upgrade rhythm. Whenever a large haul reaches the dome, allocate resources to weapon damage, tracking speed, or shield thresholds first. Once your weapon upgrades are sufficient to survive the incoming wave, invest surplus iron into Drillbert hardness and companion upgrades to fund your late-game defenses.