Let's say you wish to add a turn-started signal with two arguments: turn number and year number. You need to do this to add a new signal type; in server/scripting/script_signal.c append to signals_create: script_signal_create('turn-started', 2, API_TYPE_INT, API_TYPE_INT); Now you need to emit the signal in the proper place in the server/ code: script_signal_emit('turn-started', 2, API_TYPE_INT, turn, API_TYPE_INT, year); That's it! Hint: See server/scripting/script_signal.h for a complete list of possible argument types.