Why rushed heroes belong in the Hammer Jam

What the jam does to a hero level

The Hammer Jam runs from 1 to 16 November 2026, 08:00 UTC at both ends. ClashClock assumes it does what the 2025 edition did: half the time and half the cost of every Home Village upgrade you start inside it, Supercharges and Crafted Defenses left out. A level is priced the moment it starts and keeps that price, so a long hero level started on the last evening runs at half time to the end.

A rushed village has the most to gain, because its heroes are its longest road. Take a Town Hall 14 whose heroes stand at the maximum of Town Hall 12: it has 109 hero levels ahead, 350.7 builder days at full price. The Barbarian King alone goes from 65 to 85, 20 levels and 85.0 days. Those levels have to be built some day. In the jam the same work costs half, and the builder days it saves go to the rest of the village afterwards.

The price matters as much as the time. The top hero levels cost most of a Dark Elixir storage, so one full storage pays for one or two of them. At half price it pays for two to four, and you farm half as much Dark Elixir for the same levels.

Builder Potions are worth twice as much in the jam

A Builder Potion makes every busy builder work ten times as fast for an hour: nine hours of extra work per builder. Inside the jam every hour on a timer is two hours of full-price work, so the same potion does 18.

• Drink them while all five builders run long levels. A potion speeds up only the builders that are busy. One drunk while four builders wait does a fifth of its work.
• Keep books and hammers for after the jam. A Book of Heroes ends what is left of a level, and a Hammer of Heroes does a whole level. In the jam that level is half as long and half as dear, so either item saves half of what it saves in December.
• Start the longest level last. On the evening of 15 November, start the longest hero level you can afford. It keeps the half price to its end.

How many hero levels you get in

I gave ClashClock's planner rushed villages at Town Hall 13 to 17, each hero at the maximum of the hall two below (a hero the last hall brought at level 1), and an Own plan of nothing but the hero levels to the hall's maximum, plus the Hero Hall level they need. Five builders, eight hours of sleep, no Gold Pass, start on 1 November at 08:00 UTC. The first column of each table counts the hero levels in the plan; the others compare the plan without and with the jam.

One switch decides most of it. ClashClock keeps hero upgrades out of the Clan War League by default, from the 1st at 08:00 UTC for 11 days, so a hero is never down during a war. This November that closes 11 of the jam's 15 days to heroes, and 4 are left.

With the switch off, the jam saves 72.6 to 79.8 builder days at every hall: about 15 days of all five builders, and a sixth to a quarter of all hero work left. With the switch on it saves 20.4 to 32.5. The Grand Warden's Elixir is saved too and is not in the tables.

Stagger the days if you play the league

You do not have to choose between the league and the jam. In the league you attack once per war day, and the war days follow each other. Attack at the end of one war day and right at the start of the next, and your heroes are not needed again until the end of the war day after that: a gap of about two days. Every hero can upgrade in it, and Builder Potions speed up all of them at once.

In the jam the gaps are generous: one or no potion per gap lets every hero's next level fit at Town Hall 13 to 15, and four or five at 16 and 17, where outside the jam it takes 12 or 14. ClashClock's plan does not know your war days yet, so it cannot draw this pattern itself. Plan it with the league switch off, or with Ignore the Clan War League for this hero, and set the potions to your own times after each pair of attacks.

Simulate it in your own plan

1. Open the Hammer Jam

   It is in your plan already, as the game runs it for everyone. Tap See your time cut in What's new, or open Plan setup → Hammer Jam: the sheet says how much sooner your goal comes with the jam than without it, and how many upgrades start inside it.

   

2. Switch to Own and pick only the heroes

   Under Strategy, tap Own. If the plan already holds steps, Plan setup → Reset plan empties it. Tap Add upgrade, then the Heroes chip, and Max on each hero (or + for a few levels). Apply (Apply selection on a laptop) adds them, with the Hero Hall level they need.

   

3. Hand the levels to your builders

   Everything you add waits in Not placed: the Builders view on a phone, the Not placed tab beside Forecast on a laptop. Fill free builders gives each hero to the builder that frees up first.

4. Read what fits in

   Open Plan setup → Hammer Jam again. It now counts Upgrades starting inside it and how many are hero levels, and how much build time the jam takes off them. On the timeline the jam is a dotted band, and the Forecast's Own plan finished moves with it.

   

To keep the league as it is but let one hero through, open that hero's Hero goal & league rule in the chooser and turn on Ignore the Clan War League for this hero. To let all of them through, switch off Clan War League in Forecast.

Builder Potions in the plan, on a phone and on a laptop

The potions live in Magic items. On a phone it is a row in the Forecast view of the Plan tab; on a laptop it is in the Forecast panel to the right of the schedule. The Hammer Jam sheet has a Magic items row too.

1. Say how many you have

   Under How many, set In storage for the Builder Potion with +. The Buy rows plan a purchase with league medals or gems; what you plan to buy counts as owned.

2. Let the plan keep them for the jam

   Under When, Smart lets the plan choose the moments. With a Hammer Jam in your plan, Use during the Hammer Jam appears under it: turn it on and every potion, bought ones too, goes into the jam. The same switch sits in the Hammer Jam sheet.

   

3. Or set the times yourself

   My times → Add a time: pick the Builder Potion, How many, then Now or At a time. Use it if you stagger: one time right after each pair of attacks, when every hero has just started a level.

On a laptop you can also drag a potion's picture on the timeline to another hour; it never lands in your offline time. The Use now card on Home and Plan tells you when the plan wants a potion drunk.

Method and limits

These are simulated villages, not yours. Your own plan with your heroes, builders and hours is two taps away.

• Villages: everything of the hall below maxed, then the heroes set back to the maximum of two halls below; a hero the previous hall brought at level 1, a hero of the hall itself not built yet. Five builders, sleep from 23:00 to 07:00 UTC, no Gold Pass, helpers, Goblins or gems, nothing running at the start. Resources never stop a start.
• The jam's rules are ClashClock's assumption from the 2025 edition: half time, half cost, Home Village only, Supercharges and Crafted Defenses left out. If Supercell's announcement says otherwise, change them under Events, workers and gems.
• The league is ClashClock's assumption too: from the 1st of the month at 08:00 UTC for 11 days, with no hero upgrade planned into it while the switch is on. Your league can start and end at other hours.
• The plans leave each hero level to the first free builder. With the league switch on and no potions, Fill free builders gives the same numbers; with the switch off it can hold the Hero Hall back behind the lower hero levels, so check the Hero Hall's start on your timeline.
• Potions are placed by the plan's Smart search with Use during the Hammer Jam on. It weighs the work a potion does on the busy builders against the idle time it causes, so with the league switch on it waits for the heroes the league holds back. The staggered gaps are worked out from the game data and the potion rule, not planned: an upper estimate that assumes you start each level right after your attacks.
• The planner is greedy: each time a builder frees up it takes the best-looking step and never goes back (How ClashClock works). A better order may exist.