The resist compositions having an acid sensitive imaging polymer and a radiation sensitive acid generator component comprising: (i) a first radiation sensitive acid generator selected from the group consisting of dissolution-inhibiting acid generators, and (ii) a second radiation sensitive acid generator selected from the group consisting of unprotected acidic group-functionalized acid generators and acid labile group-protected acidic group-functionalized radiation sensitive acid generators; enables formation of high sensitivity resists suitable for use in EPL, EUV, soft x-ray, and other low energy intensity lithographic imaging applications. The resist compositions may be useful in other lithographic processes as well.