Amiga 2000 3000 or 4000

[Cammy]

As VingtTrois said, the main difference in Amiga games is the chipset they require. Most games are designed for OCS systems, while others are either enhanced for AGA or written specifically and only for AGA Amigas. You will sometimes see mention of ECS, but this was only a slight enhancement over OCS which adds more screenmodes to Workbench but wasn't ever used by games.

OCS (Original Chip-Set) Amigas include:

A1000
A2000
A500
A1500
A2500
CDTV

ECS (Enhanced Chip-Set) Amigas include:

A500+
A3000
A600
A3000T

AGA (Advanced Graphics Architecture) Amigas include:

A1200
A4000
CD32
A4000T

Sometimes games will also require a specific Kickstart ROM, CPU, or a certain amount of RAM to run. Thankfully all Amigas can be upgraded to Kickstart 3.1, the latest ROM revision, and can also make use of ROM-switcher hardware so they can keep their original Kickstart (for compatibility or nostalgia) as well as use the best. A1000s don't have a Kickstart ROM, and need to read the Kickstart from a floppy disk unless they have been hacked/modified. You can also get accelerator cards which offer faster CPUs and more RAM for all Amigas (although some of these are as rare as hens' teeth!).

[Cammy]

Cammy
You made a mistake there. Amiga 2000s can have ECS chipset as well. Most of the Amiga 2000HD had 2.x roms and ECS afaik

I made no mistake. The Amiga 2000 came out in 1986, and so was delivered with OCS until 1991 when the final revision was released with ECS and Kickstart 2.0. Since MOST A2000s were released between 1986 and 1991, not IN 1991, I was not incorrect in stating the A2000 was an OCS machine. I am aware I omitted it from the ECS list, simply to avoid redundancy and because the differences between OCS and ECS are of no consequence to games therefore hardly relevant to this topic.

[Cammy]

An intentional omission is not a mistake. Do we really need to keep going off-topic here, or will this be an endless cycle of accusations and explanations?