This is the 4357th most frequent Polish word.
graczom
"Graczom" means "to the players" in English.
The word "graczom" in this sentence is the dative plural form of the noun "gracz" (player), used to indicate the indirect object receiving something, which in this case are the maps.
Graczom rozdano nowe mapy przed rozpoczęciem gry.
The players were given new maps before starting the game.
Here, "graczom" is again in the dative plural form, showing to whom the rules were explained, acting as the recipient of the explanation.
Przewodnik wyjaśnił zasady graczom.
The guide explained the rules to the players.
"Graczom" functions as the dative plural form, specifying for whom the cheering was intended.