How likely is it that 5 players are on the same field in Monopoly? Ignoring go to jail, about 1 in 2.5 million dice rolls. Discussion, mathematical results, and improvements here: https://twitter.com/eevblog/status/1743948240616411247

monopoly.c

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

#define PLAYERS 5

uint8_t pos[PLAYERS];

int random2to12() {
    return (rand() % 11) + 2;
}

int main(void) {
    uint8_t i;
    for (i = 0; i < PLAYERS; i++) {
        pos[i] = i;
    }
    uint64_t roll = 0;
    int match = 0;
    int player = 0;
    while (1) {
        roll++;
        pos[player] += random2to12();
        pos[player] %= 40;
        player++;
        player %= PLAYERS;
        int p0 = pos[0];
        for (int i = 1; i < PLAYERS; i++) {
            if (pos[i] != p0) {
                break;
            }
            if (i == PLAYERS - 1) {
                match++;
                printf("Match %d, rolls: %llu, 1 in %i rolls\n", match, roll, roll / match);
                break;
            }
        }
    }
    return 0;
}