It tells me which box they mostly play in. From that I can pick actions which reflect that box. I might pick someone who honors the letter and spirit of the agreement, but only enters into agreements that enrich him, even if others are exploited or hurt by those agreements. I might pick to roleplay the person as someone who enters into agreements, but looks for loopholes to exploit to his benefit and the detriment of others. It doesn't matter which way I choose to do it. The two letters or two words give me the framework within to begin operating and if I want to, expand upon.
I do the latter. Now, if they kill the orcs in the fight, I don't need any more than that, but hostile is not enough to tell me what happens if the PCs decide to capture and interrogate one. Alignment helps me roleplay the unexpected social interaction.
See, to me, these two statements illustrate the main problem with alignment
and are contradictory.
First, why would PCs decide to kill or capture and interrogate some hunters? There are in-game reasons, yes: perhaps the hunters wear the livery of the king and the PCs are trying to get info on the king, whom they know or believe to be the bad guy. But--and this is, I feel, more likely--they could be capturing the hunters because they're orcs. And everyone knows orcs are evil, because every MM has said so. If I had written "elf hunters" or "human hunters" instead of orcs, would you have written this reply to me? Somehow I don't think your first thought upon seeing a group human hunters would be to kill them or capture or interrogate them.
And
this is the major danger of having alignment: it encourages lazy gameplay. There's no thought involved in either planning the encounter or playing in it, because you can just throw orcs at the PCs--even orcs doing incredibly mundane tasks like game hunting--and the first thoughts are to interrogate and/or kill them. Not negotiate with, not help out, not trade with, not follow and see if they're up to no good, not avoid. Just violence.
But as to the contradictory statements...
Imagine the PCs capture and interrogate the orc for legitimate, non-evil-listing reasons. You have the description "becomes hostile if the PCs scare away prey." So if the PCs capture the orcs and say "why did you attack us?" You have your answer right there: "You stupid humans with your clanking metal armor came into our woods and scared the deer away! Now what am I supposed to feed my kids?" The orcs
aren't going to become hostile if the PCs don't interfere with them. And you--who presumably improv
lots of different actions for your games--can decide what happens if the PCs choose to help the hunters instead.
But if you have the description "chaotic evil" then what's your answer? "You stupid humans came here and I'm evil so I attacked"? Or "Expletive deleted you, you stupid humans!"? Seriously. People keep saying that having the alignment helps guide them, but when I ask them
how, they don't answer.
But here's why it's contradictory: before, you write "It tells me which box they mostly play in. From that I can pick actions which reflect that box." But what I wrote also gives you a box--and it's a much bigger box. Why is it easier for you to pick actions out of a box marked "chaotic evil" than it is to pick actions out of a box marked "game hunters who will become hostile if their hunt is interfered with"?