Detonating projectiles are fired into a target area by a weapon, the time between firing and detonation being one second or less. By setting the target location at the same distance as e.g. the edge (1) of a building (3), however laterally displaced with respect to that edge, it is possible to obtain an effect also in an area invisible to the bearer of the weapon. For simulating this weapon, for example in house-to-house fighting, it is proposed to affix devices (5) comprising a sensor (22) and a transmitter (27) to obstacles. When the weapon is fired, a simulation device provided on the weapon transmits a firing signal to the sensor (22), the latter activating the transmitter (27). Similarly to the real effect of the weapon, the transmitter (27) emits an impact signal in the impact area (7) which also includes the mentioned area which is invisible to the bearer of the weapon. On account of the independent operation of the transceiver unit (5), it is possible to simulate the effect of this weapon substantially without delay as compared to reality.