Sucker Punch demonstrates how Infamous 2's karma system will significantly alter the game's experience.
Infamous 2 developer Sucker Punch already told us a little bit about how the game's new karma system would work, but now the studio has demonstrated it with two videos. Each shows the same mission that takes a very different turn depending on which of the karma NPCs the player chooses to follow.
The upper-right video demonstrates what happens when you follow the righteous path. Kuo, the "good" karma NPC, gets kidnapped by a local militia. By following returning buddy Zeke's lead, the player will rescue Kuo by taking down a convoy transporting imprisoned police officers, putting them back on the streets and providing Cole with a small battalion to help free Kuo.
The video below shows what happens when players follow Nix, the "bad" karma NPC. This somewhat unstable lady suggests that Cole fill up a trolley with explosives and ram it into the mansion where Kuo is being held, disregarding any collateral damage.
They're two completely separate approaches to the same mission, compared to the morality system of Infamous which basically left karma up to the player in how he/she would act during tasks, though there were missions unique to "bad" and "good" players. Brian Fleming of Sucker Punch explains that there will be a "very sizable number of missions" set up like this, with "plenty of unique content on either side." That sounds like a lot of replay value to me.