A pre-chamber arrangement (100) for a gas engine (1), including a pre-chamber body (20) accommodating a volume (30); and a supply device (50) for supplying a gaseous medium (52) into the pre-chamber volume (30); wherein the pre-chamber body (20) has a bottom portion (22) with channels (40) for allowing gas to flow between the pre-chamber volume (30) and a main combustion chamber (10) of the gas engine (1). Each channel (40) extends along a channel axis (C) from an inner opening (42) facing the pre-chamber volume (30) to an outer opening (44) configured to face the main combustion chamber (10). The bottom portion (22) has a curved outer surface (24). The channels (40) are obliquely arranged in relation to a radius (r) of the bottom portion (22). The bottom portion has flat surfaces (46) surrounding the outer openings of the channels.