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BKZ Guide — Build and Kill Zombies Guide

Roll odds calculator for Build and Kill Zombies

Every part and weapon in this game comes from a roll, and every roll label prints its odds as 1 in N. Pick one below, or type your own, and this shows how many rolls it takes to get it. It works on the printed number and nothing else; what it leaves out is listed lower down.

The game does not say how Luck applies. 1 leaves the printed odds alone; 2 assumes double the chance per roll.

Chance per roll: 0.13%, or 1 in 750

Rolls needed to get it, at three levels of certainty

520
even odds
1,726
90% sure
3,452
99% sure

The average over many attempts is 750 rolls, but half of all attempts are done within 520 rolls and about one in ten needs more than 1,726 rolls.

With 200 rolls your chance of at least one is 23%.

0%50%90%100%03,798 rolls
The three rings are the even-odds, 90% and 99% counts above.

Every 1 in N we have read, worked out

The same sums, done ahead of time for each odds figure on the screens we have seen. The bar is on a log scale, because 1 in 3 and 1 in 750 are too far apart to draw on one straight line.

  • Basic Wheel

    INDEX, wheels tab

    3
    Even odds
    2
    90% sure
    6
    99% sure
    12

  • x5 Basic Cylinder

    roll pedestal label, car parts · Common

    3
    Even odds
    2
    90% sure
    6
    99% sure
    12

  • Motor Pequeno

    INDEX, engines tab (after Update 2.5)

    3
    Even odds
    2
    90% sure
    6
    99% sure
    12

  • Hidden entry, first row

    INDEX, engines tab (after Update 2.5)

    6
    Even odds
    4
    90% sure
    13
    99% sure
    26

  • Rubber Wheel

    INDEX, wheels tab

    7
    Even odds
    5
    90% sure
    15
    99% sure
    30

  • Metal Spike

    roll pedestal label, supports · Rare

    9
    Even odds
    6
    90% sure
    20
    99% sure
    40

  • Razor Wheel

    INDEX, wheels tab

    10
    Even odds
    7
    90% sure
    22
    99% sure
    44

  • Green Smasher

    roll pedestal label, supports · Epic

    14
    Even odds
    10
    90% sure
    32
    99% sure
    63

  • Vermelho-V3

    INDEX, engines tab (after Update 2.5)

    14
    Even odds
    10
    90% sure
    32
    99% sure
    63

  • Unnamed (gold)

    INDEX, wheels tab

    18
    Even odds
    13
    90% sure
    41
    99% sure
    81

  • Double Barrel

    roll pedestal label, supports · Legendary

    18
    Even odds
    13
    90% sure
    41
    99% sure
    81

  • Rocket Turbo

    roll pedestal label, supports · Mythical

    25
    Even odds
    17
    90% sure
    57
    99% sure
    113

  • Hidden entry, first row (2)

    INDEX, engines tab (after Update 2.5)

    40
    Even odds
    28
    90% sure
    91
    99% sure
    182

  • Chama Turbo-X

    INDEX, engines tab (after Update 2.5)

    90
    Even odds
    63
    90% sure
    207
    99% sure
    413

  • X Escarlate

    INDEX, engines tab (after Update 2.5)

    150
    Even odds
    104
    90% sure
    345
    99% sure
    689

  • Unnamed (red, secret)

    INDEX, wheels tab

    250
    Even odds
    173
    90% sure
    575
    99% sure
    1,149

  • Ivy Turbo X

    INDEX, engines tab (after Update 2.5)

    375
    Even odds
    260
    90% sure
    863
    99% sure
    1,725

  • Ciber Líquido V

    INDEX, engines tab (after Update 2.5)

    750
    Even odds
    520
    90% sure
    1,726
    99% sure
    3,452

Where the numbers were read

Three kinds of screen print a 1 in N. The pedestal above a roll machine gives the odds beside a rarity word and a price. The collection screen, INDEX, keeps the odds and drops the word. After Update 2.5 its engines tab runs from 1 in 3 out to 1 in 750, then to a row of dark silhouettes whose odds are in the thousands. Those four are missing from the table because the last digits are hidden in the frame, and a guessed digit would be an invented number.

The pedestal price is left out on purpose. Nothing on screen says whether that dollar figure is the cost of a roll or the worth of the item, which is why cash per roll is a box you fill in yourself. The odds and the rarity words side by side.

A roll pedestal with the label Green Smasher above it

A roll pedestal and its label: Green Smasher, 1 in 14, Epic, $400.

Frame at 2:30 of I Built the STRONGEST CAR to SURVIVE.., recorded by Default — a player’s video, not an official image

The index screen open on its engines tab, with three rows of engines and a bottom row of dark silhouettes

The ÍNDICE screen on its Motores (engines) tab. The top row runs 1 in 3, 1 in 6, 1 in 14, 1 in 40; the second 1 in 90, 1 in 150, 1 in 375, 1 in 750. The bottom row is four dark silhouettes whose odds are in the thousands, the last reading 1 in 2?,000 with one digit hidden.

Frame at 1:36 of 7 CÓDIGOS + ATUALIZAÇÃO 2.5! 🔥 RARIDADE DIVINA | Build and Kill Zombies, recorded by BloxksReal — a player’s video, not an official image

What this leaves out

Whether 1 in N is per roll
We read it as one roll’s chance. The game never defines it. If it means something else, every number above moves.
Anything that is not pure chance
A sign beside each pedestal counts down to a locked item, and a board above the stations counts down to a reset. If either changes what a roll gives, this understates or overstates your luck, and the recordings do not show what happens at zero.
How Luck applies
Two game passes are permanent luck at two multipliers, and the skill tree has luck nodes. Neither says whether the multiplier scales the chance itself or something else, so the box is yours to set, and 1 is the safe default.
Wanting several things at once
Each figure is for one specific item. Wanting a particular engine, wheel and weapon is three separate hunts, and the machines are separate too: what pays for the rolls.