Electronic gaming device having expanding reel

A method for operating a slot type game, comprising:

• determining, by a processor using a random number generator:
• a first set of symbols chosen from a first non-expanding reel strip;
• a second set of symbols chosen from an expanding reel strip;
• and
• a third set of symbols chosen from a second non-expanding reel strip;
• displaying, on a display of an electronic gaming device:
• the first set of symbols in a first column and a second column of a playing field;
• the second set of symbols in a third column of the playing field;
• the third set of symbols in a fourth column and a fifth column of the playing field, the third column being positioned between either the first and the second column or the fourth and the fifth column;
• determining, by the processor, whether any of the second set of symbols is a special symbol;
• and
• in the event the processor determines that any of the second set of symbols is the special symbol:
• expanding a wild symbol to occupy all positions of the third column;
• temporarily inserting a sixth column into the playing field;
• and
• controlling the display to display the expanded special symbol in the sixth column.

A non-transitory computer-readable medium containing instructions which, when executed by one or more processors of one or more servers, cause the one or more processors to:

• initiate a playing field on a gaming device, by using a random number generator to assign a set of reels to the playing field;
• randomly determine, using the random number generator, when the set of reels is to be stopped, thereby determining a set of symbols to be shown on the playing field;
• determine whether a wild symbol is shown on the playing field;
• in the event the wild symbol is shown on the playing field, replacing at least one symbol in a column containing the wild symbol with an expanded wild symbol;
• wherein:
• the playing field is formed from multiple columns including a first pair of columns, a second pair of columns, and the column;
• the column is positioned between either the first pair of columns or the second pair of columns;
• a temporary column is inserted into the playing field;
• and
• at least one symbol in the temporary column is replaced with the expanded wild symbol.