Building
Tool Cupboard
Complete TC mechanics: placement, upkeep costs by tier, authorization, decay prevention, and raid defense.
Complete TC mechanics: placement, upkeep costs by tier, authorization, decay prevention, and raid defense.
The tool cupboard is the foundation of base ownership. Once placed, it grants you building privilege within its radius. This means you alone can place, upgrade, and repair structures. Lose the TC and you lose control of your base. Understanding TC placement and management is more important than any wall tier or door type.
The TC serves four critical functions. First, it prevents other players from building structures within its radius. If the TC is empty or you lose authorization, enemies can place blocks inside your base. Second, it determines who can upgrade and repair walls. Third, it manages trap authorization, so authorized players do not trigger your defenses. Fourth, it consumes upkeep materials to prevent your base from decaying.
Only one TC is allowed per base. You cannot place a second TC in the same area. The TC protects a limited radius in all directions. In very large bases, you may have walls beyond this radius that are unprotected. Testing is essential to ensure all external structures fall within the protected zone.
The TC is craftable with 1,000 wood and costs nothing to place or maintain besides the daily upkeep resources it consumes. The crafting cost is trivial compared to the cost of losing control of your base to raiders.
TC placement determines whether your base survives a raid or falls instantly. A TC placed carelessly is a TC that will be compromised. The core principle is simple: place it behind the maximum number of walls possible while still maintaining coverage of all external structures.
Never place your TC against an outer wall or accessible from outside with fewer than 2 walls between it and the exterior. If a raider destroys one wall and reaches your TC, they gain building privilege. From that moment, they can upgrade and repair your own walls while raiding you. Your defenses become their tools.
In a 2x2 base, place the TC in the corner square furthest from your entrance. In a 3x3, use the center square. In a 4x4 or larger, dedicate an entire room to the TC and seal it with doors and airlocks. The TC room should have sheet metal or armoured walls on all sides.
Example: A 3x3 base with entrances on the south wall. The TC goes in the north-center square, requiring an attacker to breach the south entrance, progress through honeycomb, break through internal walls, get past doors, and finally destroy metal walls surrounding the TC. That is 5-6 explosive hurdles before they gain privilege.
Contrast this with a TC placed in the southwest corner for convenience. One C4 through the outer wall and they own your base. The time saved by placing it centrally is not worth the risk of losing control.
Every 24 hours in-game, your TC drains a percentage of your total building costs in materials. The percentage is fixed, but the actual resource drain increases with base size. This is the hard constraint on base size: you cannot build larger than your farm can sustain.
The game calculates the total material cost of every piece in your base. The TC then drains approximately 10 percent of that total cost every 24 hours. For a stone base, this means 10 percent of your total stone cost. For mixed-tier bases, the TC drains proportionally from each material type.
Example: A 30-foundation stone base with stone walls, doors, and minimal internal decoration costs roughly 25,000 stone total to build. Your daily upkeep drain is approximately 2,500 stone. With a quarry running, this is sustainable. If your base is 50 foundations with metal walls and armoured TC room, you could be draining 5,000+ metal fragments daily, which is much harder to sustain.
| Building Tier | Daily Drain Rate | Typical Daily Cost | Strategic Notes |
|---|---|---|---|
| Twig | Decays in 1 hour | N/A | No TC protection. Only for building phase |
| Wood | 10% per 24h | 400-600 wood | Cheapest upkeep. Early-wipe temporary bases only |
| Stone | 10% per 24h | 2,000-3,000 stone | Most sustainable. Baseline for defended bases |
| Sheet Metal | 10% per 24h | 3,000-5,000 metal frags | High drain. Reserve for TC room and critical walls |
| Armoured | 10% per 24h | 500+ HQM daily equivalent | Extremely expensive. Only for vault areas |
Count every foundation, wall, floor, door, and roof in your base. Multiply each material type's count by its per-piece cost. Stone walls cost 500 stone each to build. Add them up to get your total. Your daily drain is 10 percent of that total.
A small 2x2 stone base (4 foundations, ~16 walls, 2 doors, 1 roof) costs roughly 9,000 stone to build. Daily upkeep is 900 stone. With three furnaces smelting ore, this is easily sustainable.
A large 10x10 stone compound (100 foundations, ~300 walls, 10 doors, complex layout) costs 150,000+ stone to build. Daily upkeep is 15,000 stone. Only groups with serious mining operations can maintain this consistently.
If your TC depletes to zero resources, decay begins immediately. Outer walls decay first. Within 24 hours, outer walls become visibly damaged. Within 48 hours, they collapse. Loot becomes exposed and raidable by anyone. Check your TC every login. If you plan offline time beyond 3-4 days, fill it to maximum before logging.
Only authorized players can use the hammer on building pieces. Everyone else is locked out completely. Approach your TC with E and click "Authorize." This adds your player ID to the auth list. Teammates must authorize individually. Each person remains authorized until manually removed.
Authorized players do not trigger shotgun traps, flame turrets, or auto turrets. Unauthorized players do. When bringing teammates into your base, make sure they authorize first, then test that traps do not activate. Nothing destroys team morale like friendly fire from your own defenses.
Deauthorize people the moment they leave your group or show signs of betrayal. Do not wait until they are online again to remove them. Authorization is revoked instantly whether they are online or offline.
Test your TC coverage before finalizing your base layout. Walk around your intended base perimeter and verify all external walls fall within the TC radius. If you have honeycomb walls or external structures (like furnaces or vehicle storage), confirm they are protected.
If you have a very large compound where parts extend beyond the TC radius, you must either restructure to fit within coverage or accept that those distant structures are not protected. Some large compounds use stacked TCs with overlapping radius coverage, but this is resource-intensive and only worth it for very large group bases.
See the principles of building guide for general base layout strategy and the upkeep guide for detailed cost calculations by base type.
Mistake one: Placing the TC where it is accessible after one wall is destroyed. This defeats the entire purpose. Your TC should require breaking through multiple walls or doors to reach.
Mistake two: Not refilling upkeep regularly. Set a daily habit. Every time you log in, check the TC. If it is below 75 percent full, refill it immediately. This takes 30 seconds and prevents catastrophic decay.
Mistake three: Authorizing too many players. Each additional person is a potential liability. Keep the auth list minimal. Remove anyone inactive for more than one week.
Mistake four: Not protecting the TC room. The TC room should be sealed with doors and an airlock. An accessible TC room is a compromised TC room.
Mistake five: Building without calculating upkeep sustainability. A massive base might look impressive but be impossible to maintain. Build for what you can farm consistently, not for prestige. A maintained 2x2 is worth more than a decayed 10x10.
More experienced Rust players think about TC placement and protection before they think about anything else. Every base design decision ultimately serves to protect the TC. Airlock placement controls how close attackers can get. Honeycomb forces them to waste explosives before reaching the TC. Internal walls and doors create multiple break points. Advanced techniques like bunkers and shoot floors exist primarily to delay and punish any attempt on the TC.
Losing a TC room to raiders costs you the entire base. Protecting it should be your first design priority, not an afterthought.