It's a bit old and is for first edition, but much of it is still golden, especially the GM advice.
I suppose everyone else has already rung in on instant death (a previous post). It really isn't necessary, in fact any attempt to make the Con-X damage system MORE lethal is ill-advised. I myself multiplied the stabilization times by five so you could at least have the medic walk over to someone with Splatter 3 before they died. But I kept the original Heal Mods so unless you are highly skilled with a Paramedic kit it's going to be difficult. It's safe to say someone who takes Splatter 3 is out of the game in either case. Players should at least be given the courtesy of rolling luck to survive. Also note that according to the rules if you take flesh wound six and you fail your stabilization test you die. It does NOT carry over to the next lethal damage level. Damage that is inflicted carries over but if you ever go over six levels of damage do to failure to stabilize you die.
Nobody has ever said to me in the years I've been playing that the game wasn't lethal enough.
In either case. Here's a few tips.
1. Explain to your players that being shot has a distinct chance of resulting in death. Many modern-era RPG's don't relfect this accurately.
2. If you use the "fear" rules expalin there's a good chance
characters will go insane. It's not QUITE as bad as Call of Cthulu but it's close.
3. Encourage players to aquire kevlar vests and pistols.
4. Con-X is a "skill-focused" system primarily. Having a relevant skill is more useful then having a relevant stat.
5. Almost every stat is useful though. Having all 3s is not bad at all. But lowering a stat to two or rasing it to three can have major consequences. A 2 INT means you have a learning disability. A 4 Ref means you always go first in combat. If players MUST lower a stat the best one to do this with appears to be Agility. Note there is no Attractiveness/Charisma stat. Tell players they can be as attractive as they want to be, if they go overboard give them the distinguishing mark flaw.
6. Discourage players from lowering too many stats or taking too many flaws. Especially taking stats to one or flaws that make little or no logical sense.
7. The stat and skill system is exponential in many cases not linear. A Martial Arts 3 person will almost always destroy a Martial Arts 2 person.
8. Depending how you decide to introduce aliens and the paranomal (if at all) in your game, explain how difficult (suicidal) Aegis thinks a direct confrontation would be. Of course this depends on how "well" you decide to play the opposition.
9. Don't let players take Natural Learner if you know what that is. It's surprisingly unbalancing.
10. If you use the Con-X initiative system (which I do). Explain that there's a distinct chance of two people shooting each other. This is why getting the drop on your target or taking snap shots is so important.
11. If at all possible, cells should include a medic. It helps if
everyone has at least one combat skill. You would be surprised how often one extra gun makes the difference.
As a GM
1. Consider stuffing the game full of organization, plots, and
counter-plots. Always have at least three sides in any confrontation.
2. Consider stuffing the cell with hooks. Players can be secret
hypnotized traitors, thier parents are incarnate, double-agents for a even more secretive organization, abducted. Nothing says you have to tell the players this. If you feel sorry about stackign the deck against them give them some extra CPs.
3. If you decide to use all the options, powers, and abilities of the supernatural and extraterrestial forces available to you, do not ever put them in direct confrontation with the players without givng the players some possible massive advantage. Low-level incarnate and Men In Black are reasonable opponents. Any Atlantean, armed Saurian, or aware Grey is well nigh unstoppable without significant preperation.
4. Don't be afraid to lie to the players, do it often actually. Black Book lies, Aegis lies, NPC's can lie. Listen to the cosnpiracy theories players tell to try to patch all the lies together. Consider building on their wild ideas or making up more lies. Try making up random details and watch the players try to string them together. Lie some more.
5. Don't put players in direct confrontation with ohter players too often. Players shooting at other players is no less lethal.
6. Don't be afraid of killing a player, it's really in the spirit of
the game. Ask if someone would be able to survive it in real life, do research if you must. If you feel bad make them roll luck to survive.
7. When in doubt about wheather something should happen or not roll the luck of a random player or the luck of the player the event most effects.
8. Don't be afraid to modify skills by +1t, -2t, +1DF, etc. There are lots of wacky situations players will get themselves into.
9. If you like the game consider buying Sub Rosa easily the best core-rules addition.