A computer-implemented method involving a software application executed by a server computing system on behalf of a client computing system with a display screen, wherein:
- the server computing system and the client computing system are configured to communicate with each other using a communication network,
- a memory of the client computing system stores a global symbol group including a plurality of symbols, subsets of which are displayable in a respective vertical symbol display segment of the display screen,
- a hierarchy of symbols for the software application defines an order of multiple symbols of the global symbol group arranged from a lowest priority to a highest priority,
- the multiple symbols include at least first and second symbols of the global symbol group,
- the display screen is configured to graphically display, on multiple vertical symbol display segments, animations that simulate a spinning of a plurality of reels,
- the display screen includes multiple particular patterns, each particular pattern comprises one symbol position from each reel across the plurality of reels, and
- the computer-implemented method comprises:
- receiving, by a processor at the server computing system, a first communication, wherein the first communication includes:
- a spin request and first data indicating a first set of particular patterns selected to be active for a first outcome;
- selecting, by the processor after receiving the first communication, a set of symbols within the global symbol group for displaying on the display screen in a first arrangement, wherein the first arrangement defines respective symbol positions for each symbol of the set of symbols to indicate how to display the set of symbols within the vertical symbol display segments, wherein first symbol data indicates the set of symbols and the first arrangement;
- determining, by the processor based on the set of symbols according to the first arrangement, whether the symbols in each particular pattern of the first set of particular patterns form a winning pattern for the first outcome, wherein each winning pattern for the first outcome comprises the first symbol being in two or more symbol positions of a respective particular pattern of the first set of particular patterns, and first pattern data indicates a second set of particular patterns, each of which is a winning pattern for the first outcome;
- transmitting, by the processor, a second communication to cause the display screen to display a first animation that simulates spinning and stopping the reels, wherein:
- the second communication includes the first symbol data and the first pattern data, and
- stopping the reels results in the vertical symbol display segments displaying the set of symbols according to the first arrangement and an indication of each winning pattern for the first outcome;
- receiving, by the processor, a third communication after transmitting the second communication, wherein the third communication includes an upgrade request;
- determining, by the processor, the first symbol within each winning pattern for the first outcome is contained within the hierarchy of symbols and does not have the highest priority in the hierarchy of symbols;
- determining, by the processor based on the hierarchy of symbols, the second symbol is an upgrade symbol with an increased value relative to the first symbol;
- determining, by the processor, second symbol data that indicates which symbol positions within at least the second set of particular patterns contain the first symbol and are to be transformed to contain the second symbol instead of the first symbol;
- determining, by the processor based on the first and second symbol data, whether the symbols in the symbol positions in each particular pattern of at least the second set of particular patterns form a winning pattern for a second outcome, wherein:
- each winning pattern for the second outcome comprises the second symbol being in two or more symbol positions of a respective particular pattern of at least the second set of particular patterns, and
- the second symbol in at least one particular symbol position of each winning pattern for the second outcome is an initial symbol selected for the at least one particular symbol position in the first arrangement,
- and second pattern data indicates a third set of particular patterns, each of which is a winning pattern for the second outcome;
- and
- transmitting, by the processor, a fourth communication to cause the display screen to display a second animation and an indication of each winning pattern for the second outcome, wherein:
- the fourth communication includes the second symbol data and the second pattern data, and
- the second animation simulates transformation of the first symbol in each winning pattern for the first outcome to the second symbol from the global symbol group stored at the client computing system thereby displaying the second outcome;
- causing the client computing system to output a corresponding award for each winning pattern for the first outcome and the second outcome, wherein each winning pattern for the second outcome that includes the same symbol positions as a winning pattern for the first outcome corresponds to an award with an increased value relative to an award corresponding to the winning pattern for the first outcome due to transformation of the first symbol to the second symbol.