A Kickstart 3.1.4 ROM (desirable), or an old Kickstart 3.1 ROM (not the best choice since you will have 3.1.4 loading ROM modules and this will eat extra RAM, take more time to boot, will not provide several AutoConfig fixes, and will give you an additional reboot. Furthermore, you won't be able to directly boot into partitions outside the first 4 GB of your hard disk).
2 MB of total RAM (total memory is calculated by adding up Chip RAM and Fast RAM altogether).
5 MB of free hard disk space.
And of course, a sufficiently compatible Amiga machine is needed (Nowadays, this is important to state because we have a lot of Amiga clones, and there is a possibility a couple of them will fail somewhere due to bad and/or missing Amiga hardware re-implementation).