Climate change is likely to strengthen abiotic stresses on crops in temperate zones. Grain legumes and the associated provision of ecosystem services are the cornerstone of more sustainable cropping systems, yet the impact of climate change on their performance has not been extensively quantified. Based on previous experiments carried out in south-western France with low biotic stress, we calibrated the STICS soil-crop model for spring pea (SP), winter pea (WP) and winter faba bean (WF) grown on two types of soil with available soil water ranging from 64 to 167 mm and evaluated its quality of prediction on an independent dataset. STICS was used to explore the effect of climate change scenarios on the legumes performance. Assuming no adaption of crop management, mean and inter-annual variability of grain yield and N2 fixation were assessed for historical (1995-2015), mid-term (2020- 2040) and long-term (2060-2080) periods, considering projections from two coupled atmosphere-ocean Global Circulating Models (GCM), and two Representative CO2 Concentration Pathways (RCP), i.e. RCP 4.5 and RCP 8.5. The GCMs consistently predicted no significant change in rainfall amounts but indicated a 1.7°C and 2.5°C increase in average temperature over the growth period in the long term under RCP 4.5 and RCP 8.5 respectively. Therefore, simulations indicated no extra water stress with future climate. The increase in temperature entailed a shortening in crop duration and a slight but significant increase in the temperature stress factor values for grain filling, for photosynthesis and for N2 fixation during the reproductive period (+1% to +13 % depending on temperature stress, crop and RCP). Under RCP 4.5, yield decreased by 23 to 34% (depending on crop) in the long term. Average fixed N2 decreased by 16% to 34%. Probability of yield failure (i.e. yield below the 20th percentile of historical yield) increased from 20 to 50, 54 and 58% for WF, WP and SP respectively. Probability of N2 fi