The present invention provides a system for simulating a reaction force from a virtual object. The system at least comprises an input force sensor, calculating means connected to the input force sensor, at least a first pair (201a, 201b) of linear resonant actuators (LRAs) and a driver for the LRAs connected to the calculating means. The input force sensor is to sense an input force applied to the virtual object by a user. The calculating means is to receive the input force from the input force sensor and to calculate the reaction force to apply to the user. The pair of LRAs (201a, 201b) are constrained to move along a first axis (Y). The driver is to receive from the calculating means drive signals to alternately drive each one of the pair of LRAs (201a, 201b) in a first direction along the first axis by an amount determined by the reaction force, whilst allowing the other one of the pair of LRAs to recover more gently in a direction opposite to the first direction. The invention also provides a corresponding method of simulating a reaction force from a virtual object and a mobile device (101) at least comprising such a system.