From what I can tell, the owners of Deus Ex have been secretly
stepping down the price for years. Now it is, for all intents and purposes, free. I if and when they'll take it off GameTap's free list.
Start SpoilersIn order to keep paul alive, you have to stay with him when he tells you to leave the hotel room after his kill-switch was activated. Basically, help him fight off all of the numerous UNATCO/MJ12 agents in the hotel and make sure he survives until he leaves on his own. You'll later meet him in alive in the MJ12 facility beneath the UNATCO building on Liberty Island. After that, he's with Tracer Tong in Hong Kong.
You can get Anna Navarre's killphrase in two parts right before you escape UNATCO and have to fight her. The first half is on her computer and the other half is on Manderley's computer. I've never used it because I have usually killed Anna before this point anyway.
In order to get Gunther's killphrase, you have to tell Jamie to stay at UNATCO, while you are escaping. If you do, you should meet him at a café in Paris wherein he tells you the phrase. You can then use against Gunther it when you're doing the mission with the Templar's gold and all that.
End SpoilersThat's what I love about Deus Ex, just the incredible freedom to discover plot forks and shortcuts completely on your own. Most games have glaring neon signs every time there's a split in the path.
P.S. Wouldn't suck if you were on a mission and someone, by pure chance, accidentally said your killphrase?