找到了荒野大镖客年度版HC模式的官方解释

jackylll

Aiming is permanently set to Expert.
Maximum health is reduced by half.
Health regenerates more slowly and begins refilling after a longer delay.
Dead-eye does not automatically fill over time. It must be earned by killing enemies or using items.
Horses do not regenerate. If killed, you must purchase, steal, mount, or break another horse and then hitch it to a post to earn the right to call it by whistling.  Note that horse deeds are still available and unlimited, but twice as expensive.
Store items cost more. Sell values are lowered.
Reward/drops/looting amounts are lowered (ammunition and money).
Pardon letters are more rare.
Fame and Honor gains are reduced.
Mini-game buy-ins are lowered to match the scarcity of money.
Warhorse deed must be purchased for $10,000 (available in any General Store).
Deadly Assassin outfit increases the amount of Deadeye gained from kills, rather than over-time regeneration.
Note that Hardcore is only available in the normal Red Dead Redemption campaign -- Undead Nightmare is unaffected.

翻译一下也就是说瞄准更难了  血更少了
死亡之眼只能靠杀人来增加 平时用完就没了 除了***  而且杀手服装只是杀人以后增加的更多一些 平时并不会增加死亡之眼
马不能复生 死了就死了 重新买 或者用其他的方法搞马 这点还是比较真实 之前的马实在是太不值钱了

商店里东西更贵 你卖的确更便宜
PARDON LETTERS更稀有
FMAE和名誉值增加更少
等等

总之HC模式只能在本片中玩，僵尸DLC中是没有的  

想飞的水滴

了解啦，谢谢楼主分享信息，辛苦了