What does the 6th builder (B.O.B.) really cost?

What the seven requirements add up to

B.O.B. moves in when B.O.B Control reaches level 5, and it only gets there once the other six requirements are met: three gear-ups in the Home Village, a Builder Base troop at level 18, a defence at level 9 and the Battle Machine and Battle Copter at a combined level 45. The 6th builder guide lists them. Here I put a price on them.

I ran ClashClock's own B.O.B. path on a fresh Builder Base, Builder Hall 1 with nothing built, with the three Home Village defences already at the levels the gear-ups ask for (Cannon 7, Archer Tower 10, Mortar 8), so the home side is only the gear-up fees. The path is 77 steps long.

The Master Builder's share is 215 days of Builder Base upgrades plus the 23 days the three gear-ups keep him busy: 238 days. These are the figures of the one-builder path, which builds the Clock Tower to level 8; with two or three builders the path stops the tower at level 7, which is 3 days less tower work. The Star Laboratory works beside him for 41.5 days, taking the Baby Dragon from level 5 to 18, and it needs about 21 days of builder time itself to reach level 9. The gear-ups cost 1, 3 and 6 million gold and take 2, 7 and 14 days. The village that can do all of it is a Town Hall 10 village with Builder Hall 9.

What dominates the timeline

The heroes. Battle Machine to level 23 is 63 days and Battle Copter from 15 to 22 is 35, together 98 days, which is 41 % of the Master Builder's 238. The split between the two hardly changes the work: the six splits from 20 + 25 to 25 + 20 all take 98 days in total, the further you go from the middle the more it costs, and the tracker's path takes 23 + 22. It can change the calendar, though: with two builders, 22 + 23 arrives 5 days sooner than the tracker's 23 + 22.

Second comes the Multi Mortar, 38.8 days. It is the defence requirement and a building the Mortar gear-up needs at once. The gear-up asks for level 8, so the defence requirement itself adds only level 9: 11 days and 4.5 million Builder Gold. Every other defence is worse. Forced through the path, they add between 4 days (Archer Tower) and 53 days (Mega Tesla, Lava Launcher) to the whole job.

Next are the storages: 24.8 days, 9 % of all the work, because the game starts an upgrade only when its price fits and the path raises storages before the expensive hero and troop levels. Then come the gear-ups (23 days), the Builder Barracks and Star Laboratory (21) and the Builder Hall (21).

Some of this a third builder cannot shorten. A hero cannot be upgraded by two builders at once, so the Battle Machine's levels 2 to 23 are one chain of 63 days of upgrades. With two builders it runs unbroken from day 70.1 to day 133.1, and that is the day B.O.B. arrives. With three builders from day one it starts on day 5.4, with 26.2 days of waiting in between, and ends on day 94.6. The last 12 days of that schedule hold nothing but the two heroes: three Battle Machine upgrades (levels 21 to 23) and three Battle Copter upgrades (levels 20 to 22), side by side. The first of each began up to 5 days before that window.

How many builders you have

A new Builder Base has the Master Builder alone. O.T.T.O. joins with Builder Hall 6, B.O.T.O., bought with gems, can come earlier, and three is the most a Builder Base ever has. The path's own estimate divides the builder work by the number of builders, on the path for that many builders. The planner's schedule, which is the number the Plan tab shows, comes out longer. Each row below fixes the builder count from the first day, which a real Builder Base cannot do for three, so the three-builder row is a floor, not a date you can reach.

Three things separate the columns. The gear-ups run on the Master Builder, and the path's estimate leaves their 23 days out. The schedule also builds the plots each hall opens before the next hall goes up, as the planner assumes the game requires: that is 16 days with one builder, 9.5 of them Army Camps, whose cost and build time grow with every camp you own. And the steps wait for each other, the Builder Hall for the Star Laboratory, the Star Laboratory for the troop, so extra builders find less to do.

A realistic start without B.O.T.O. is the one-builder row until Builder Hall 6, which one builder reaches on day 11, and then O.T.T.O. as the second builder. Re-planning from that day gives day 137, against 133 for two builders from the start. Once the Clock Tower stands, the tracker credits its boost and the same village shows day 121. If you buy B.O.T.O. on the first day you start with the two-builder row, and O.T.T.O. becomes the third builder when Builder Hall 6 stands, on day 9. Re-planned from there, B.O.B. arrives on day 101, against 96 for three builders from the start; with the tower's boost credited it is day 89. The Gold Pass applies in the Builder Base too: at 20 % it takes 52 days off the one-builder schedule, 28 off the two-builder one and 21 off the three-builder one.

The Clock Tower

The Clock Tower runs every Builder Base upgrade at ten times speed for a few minutes, so each minute saves nine. The game data gives 14 minutes at level 1 and 32 at level 10, which is 2.1 to 4.8 hours saved on every running upgrade per use. The planner assumes one use every 22 hours.

The path decides how much tower to build by weighing its build time against what the boost wins back before B.O.B. arrives. With one builder it builds the tower to level 8, 7.1 days of work. With two or three it stops at level 7, 4.1 days.

What is the boost worth? I put a finished tower into the village on day one and ran the schedule twice, once with the boost switched off and once on. That is an upper bound, because a real tower arrives later.

A level 8 tower from the first day brings B.O.B. 15 to 17 % sooner, 36 days with one builder and 17 with three. One caveat about the tracker: the Plan tab credits the boost only for a tower that already stands when the plan is made. A fresh village shows a date with no boost even though the path builds the tower, so that date is on the long side until the tower is up.

Which troop and which defence

The requirement says any troop at level 18. The tracker's default is the Baby Dragon: 41.5 days in the lab and 256.6 days of builder and lab work for the whole path, not counting the 23 days of gear-ups. Of the twelve troops that can reach 18, eleven lie between 250.0 and 257.0 days, within 3 % of each other. The Hog Glider is the shortest, with the Baby Dragon 6.6 days behind, and the Electrofire Wizard is the outlier at 268.5, because it needs 262.5 days of builder time against 215.1. Pick the troop you want to attack with. The defence is the opposite: the Multi Mortar wins because the Mortar gear-up has already paid for most of it.

What the sixth builder gets you

Mostly earlier buildings. In the planner runs from my Town Hall post, a Town Hall 16 village with six builders instead of five finishes its buildings on day 1,187 instead of 1,216, 30 days or 2.5 % sooner, but the whole village only 6 days sooner, because the Laboratory is the last lane. At Town Hall 12 the step is 20 days (6.2 %) for the buildings and 5 for the village. The work to get there is almost all in the Builder Base, plus 10 million gold at home.

Method and limits

The numbers come from ClashClock's own code run on its game data, so they are the ones the tracker shows. The path is what the Plan tab prints for totals. The schedule is the planner on the 6th builder strategy, read at the date B.O.B. Control reaches level 5, which is the Plan tab's headline.

• A fresh Builder Base: Builder Hall 1, nothing built. The Home Village defences stand at the gear-up levels. If yours are lower, those levels are home work on top.
• The path counts what the requirements demand plus the Builder Hall, storage and Clock Tower steps it inserts. The schedule adds the plots each hall opens, as the planner's rule has it.
• No offline hours, potions or helpers. The Gold Pass only where it is named. The builder count is fixed for each run, and the totals are the one-builder path's (Clock Tower to level 8). A Builder Base cannot start with three builders, so the three-builder rows are floors; the reachable way to three builders is the re-plan on day 9 above.
• The Clock Tower's 22-hour recharge is the planner's assumption and is marked unverified in its code. The tower figures are upper bounds.
• I forced four other Battle Machine and Battle Copter splits through the schedule. With two builders, 22 + 23 is 5 days faster than the tracker's 23 + 22; with three builders the tracker's split is the best of the five.
• The seven requirements and the gear-up fees are the ones the 6th builder guide prints; both read the same game data. Game data changes with updates, and the times above move with them.