What decides the size of a Hammer win in 12 Bolts of Thunder?
The number of Hammers and, in the free spins, the level of the table. They appear on the three middle reels alone, and four or more anywhere there are paid by count from the Hammer Paytable beside the grid, on top of any line wins: 2x the bet for four, 10x for six, 20x for eight and 1,000x for all twelve. In the free spins every Hammer win also adds 3 spins and moves each count up to the next count's value, five times at most, until twelve Hammers are worth 30,000x.
Twelve cells on three reels, paid by how many Hammers they hold
Only the middle three reels carry Hammers, four cells each, so one spin can show twelve at most. Four or more make a Hammer win, worth 2x, 5x and 10x for four to six, then 15x, 20x and 50x up to nine, and 100x, 500x and 1,000x for the last three. Thunderkick's page calls the Hammer the Mjolnir symbol.
The Hammers do not have to touch. On spin 504 reels 2 and 4 were full of them and reel 3 had none, and the server still paid eight Hammers, €20.00. The Wild, a green shield with a golden W, substitutes for the line symbols only, never for a Hammer or the Bonus door.
Lines are the ordinary part. There are 20 of them on five reels of four rows (the rules write 4x5, rows first), each paid left to right without gaps. With €1.00 staked, three, four and five 777s pay €2.50, €3.50 and €20.00, BARs €2.00, €3.00 and €15.00, and bells, horseshoes and card ranks less, down to €0.50 for three cards.
Across our 750 paid spins the base game produced 18 Hammer wins worth €131.00, 8 of them the four-Hammer minimum. Near misses were the rule: two Hammers showed on 151 spins and three, one short, on 139. Small as the feature looks, 7 of our 9 base-game results of 10x or better were Hammer wins.
Three more spins and a richer table after every Hammer win
Bonus doors can land on any reel. Three open the Bonus Game and are worth 6 free spins, four gave 9 in our log, and the five on our filmed purchase gave 12. Inside the round the Hammer Paytable stops being fixed.
Rules page 3 has every Hammer win in the free spins paid first, after which it upgrades each level of the table, five upgrades at most, with 30,000x for twelve Hammers at the top. Our logs add something the captured text leaves out, 3 more free spins after each Hammer win, which are the retriggers that Thunderkick's game page mentions. Read side by side, the two tables in the rules show the step. After one upgrade four Hammers are worth 5x, what five paid before, and twelve are worth 2,000x.
Every Hammer win in the server's answers followed that step. The level counter starts at 1, and with each Hammer win a count pays what one Hammer more paid a level lower: four Hammers brought 2x, 5x, 10x and 15x on levels 1 to 4 and 50x on level 6, and nine Hammers on level 2 paid 100x. The counter never passed 6. In the filmed round the panel beside the reels showed the same number, LEVEL 1 to LEVEL 5, with the whole column of values moving up each time.
In our capture the sixth and last table appears only on the intro screen, dimmed: 50X for four Hammers up to 15000X for eleven, the twelve row hidden by a glow that the rules fill in as 30,000x. Our first control buy reached it, and four Hammers there paid €50.00.
Hammer wins carried our bonus rounds. In the 54 free spins of the three natural rounds there were 10 of them, together €220.00 out of €242.50; the lines added the rest.
By spin 705 base-game Hammers had outearned the free spins
Our stake of €1.00 over 750 paid spins added up to €750.00. Wins returned €647.00 of it, 86.3% against a listed 96.15%. Free spins paid €242.50 of that and the base game, its Hammer wins included, €404.50.
- 750paid spins at €1.00 in the demo
- 86.3%of the stakes paid back
- 168.5xbest round, free spins included
- 3free spins rounds triggered
The first two bonus rounds stayed small. Spin 129's round opened with three doors, two Hammer wins of 5x each took it from 6 free spins to 12, and it ended at 23.5x with the trigger spin's line wins. Four doors and 9 spins started the next, on spin 183; four Hammer wins took it to 21, and it paid 54.5x.
As early as spin 8 the balance had peaked at €5,018.50, and by spin 705 it had fallen to its lowest, €4,753.50. At that point base-game Hammer wins had paid €129.00 and free spins €75.00. Spin 706 then brought four doors, and its four Hammer wins paid €20.00, €100.00, €20.00 and €20.00. The second, nine Hammers on the table after one upgrade, was worth 100x, and the round ended at 168.5x, the best of the session.
Across the session wins arrived on 19.9% of spins, half of them at 2x or less, and the longest run of losses lasted 35. The best base spin, 30x on spin 626, came entirely from two lines of five BARs.
Three purchases at €100.00, and how far the Hammers stretched them
Just one card sits in the buy menu, the Bonus Game at 100x the bet, or €100.00 at our stake.
Its RTP on the demo server, 96.50%, sits a little above the 96.15% of paid spins. That second figure is the one on Thunderkick's game page and the version this demo plays. Two more versions, at 94.12% and 87.19%, appear in the studio's game information sheet, and a casino's copy of the game could carry either. According to the launch announcement, the buy was offered only in some regions.
| Option | Price | At €1.00 | RTP of the buy |
|---|---|---|---|
| Bonus Game | 100x | €100.00 | 96.50% |
Both control buys landed three doors and 6 free spins, and the Hammers took it from there. The first collected 6 Hammer wins, reached the top level on free spin 12 and ran to 24 spins for €203.50. The second managed 4 Hammer wins in 18 spins and paid €36.50.
That purchase began with more spins than any other round we logged, 12, and still came in at about a fifth of the first control buy. Its Hammers came four at a time, the minimum, on free spins 1, 5, 12 and 19, so each upgrade raised a table that the next win used only at its bottom row. After 24 spins it closed at €39.50, about two fifths of the price.
Mjolnir without Thor, and the Norse game it sits beside
Under the Norse name sit the 777s, BARs and bells of a fruit machine, with the Hammer as the one mythological piece. Thor himself does not appear.
Nearest to it on this site is Second Thunder, from February 2026, sharing the theme and high volatility. No source we found links the two as a series, and the numbers differ throughout: 50 paylines on six reels, 94.20%, a 12,500x cap and a buy at 75x, against 20 lines, 96.15%, 30,000x and 100x here.
The idea is simple. Most spins pay little or nothing, three Hammers turn up far more often than four, and a bonus round is only as good as the Hammer wins it collects, since each one both extends the round and raises the table for the next.
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On these four points the captured rules fall short, so the answers come from what the demo server sent back during our rounds.
Do the Hammers have to land next to each other?
No. They count anywhere on reels 2, 3 and 4: on spin 504 the server paid eight of them at 20x the bet with none on reel 3. Wilds never stand in for a Hammer, so a Hammer win depends on Hammers alone.
Does the upgraded table carry over into the base game?
No. Every Hammer win of our base game paid the base table, including those that came soon after a bonus round: on spin 723, after the round on spin 706 had reached its fifth level, four Hammers paid 2x again. Each Bonus Game in our log also began from the base values.
Do four or five Bonus symbols start the free spins on a better table?
Not in our rounds. Spins 183 and 706 began with four Bonus symbols and 9 free spins, our filmed purchase with five and 12, and all three started on the base table: the first Hammer win paid eight Hammers at 20x in the two natural rounds and four at 2x in the purchase. More symbols changed the spin count only.
What happens to Hammer wins after the fifth upgrade?
They keep paying from the top table and keep adding spins. In our first control buy the fifth upgrade came on free spin 12, after six Hammers paid €100.00. On free spin 18 four Hammers paid €50.00, and the counter still gained three free spins.