RDR2 (2018) is what any new Rockstar open world will inevitably be compared to. It raised the bar for fidelity, wildlife and density in a non-urban world. GTA 6 will be held to this standard whether it's fair or not.

We explore where the comparison applies and where it doesn't. For the general size question, see the map size piece.

Where RDR2 actually set the bar

Wildlife - large ecosystem, behavioural AI, predator/prey logic. NPC density - even small towns had believable population levels. Audio occlusion - how sound travelled through the world. Environmental fidelity - weather, seasons, terrain details.

Rockstar can clear some of these bars. Others are RDR2-specific due to the genre. Open-world wildlife in a 19th-century western is a wholly different problem to open-world wildlife in 2020s Florida.

What GTA 6 has to do differently

Density of urban content - RDR2 featured towns; GTA 6 features Vice City. The challenge is different. Rockstar didn't have to handle downtown crowds of 1,000 NPCs in RDR2. In GTA 6, it does.

Pace. RDR2 was intentionally slow; GTA 6 won't be. The physics, vehicle handling and even how missions play out minute to minute will all feel very different.

Where the comparison fails

Overall map size. Red Dead Redemption 2 already offers a sizeable map to play in; GTA 6's might be bigger or smaller. The comparison doesn't tell you anything about how it plays, since the two games take divergent approaches.

Wildlife depth. Yes, there will be wildlife in GTA 6 - alligators are visible. Whether it'll have RDR2-calibre ecosystem AI is another question entirely, and probably the answer is no - GTA wildlife has historically been on the lighter side compared to RDR's, by design.

What we can fairly say

GTA 6 will be denser than GTA 5, and almost assuredly denser than the settled environments of RDR2. GTA 6 will have a smaller overall physical map size than what RDR2 covered. GTA 6's animal life will lack the ecology depth of RDR2's. GTA 6 will run heavier on pedestrian AI than any game Rockstar has released.

All of the above is informed expectation, not a promise.