Hit points are, as mentioned earlier, your STR score + 1d6 per level. Attacks will remove hit points. When HP reaches 0, the character is unconscious and near death. Any additional damage directly reduces STR. If STR reaches 0, then the character is dead. Most NPC antagonists follow these same rules, but certain NPC antagonists are considered "mooks" (also minions, goons, spear-carriers, etc.) and are not meant to keep fighting after being hit. These characters don't have any hit points, and any successful attack in combat will automatically kill (or at least incapacitate, if you're playing a less violent game) them outright. A good example would be most stormtroopers and battle droids. They are, however, assumed to have all of the other stats as any other character. A super battle droid could be a mook who goes down with only one hit, but because he has heavy armor and a high STR, he still makes a more formidable opponent than a regular battle droid. For example.
Combat is conducted in initiative order. Roll 1d20 + DEX to determine initiative order. Everyone can do two things during a combat round, (1) move and (2) move, attack, deflect a blaster bolt (if a Knight using a lightsaber), use a skill, etc. All checks or attacks target a DC, either a skill DC for skill checks, an opposed skill check result for opposed skill checks, or the target's Armor Class (AC) for attack rolls. Although a move is considered 30 feet, I'm not interested in using a battle-mat, or overly tactical combat, so that's more of an abstraction than anything else. Remember how you used to play D&D back in the 80s without mapping out combat unless it got really excessively complicated due to lots of opponents? That's how Star Wars should feel--combat is fast and loose and swashbucklery, not static and grid-based and miniatures game like. To facilitate this, unlike in D&D or most other d20 games, it's not assumed that you must Move and then take your move equivalent action (be it an attack, using the Force, or whatever)--rather, you are assumed to do them at the same time. This means that in d20 terms, all characters are automatically assumed to have the equivalent of the Spring Attack feat. If you don't play d20, and since this isn't a tactical combat assumption anyway, that may be irrelevant.
- Melee attacks are made as a STR + attack bonus (usually level, but for Soldiers and for Knight's using lightsabers it can be higher). Add your STR bonus to damage as well.
- Ranged attacks are made as DEX + attack bonus. This includes both shooting a blaster (or other gun) as well as throwing something, such as a grenade.
You may also take damage from other things than simply combat attacks. Here's a few examples:
- Falling: A character takes 1d6 damage for every ten feet fallen. You can reduce this damage by trying to land lightly by making a DEX + Physical skill check with a DC equal to the number of feet fallen. This will result in only half of the damage taken (rounded up.) The Force Surge power can be used in a similar way.
- Hazards: When falling into a hazard, such as spikes, or something like that, at +1 point to the falling damage for every ten feet fallen, max +10.
- Poison: Make a STR + Physical skill check to avoid or for half, depending on the poison. The effect depends on the specific poison.
- Extreme Heat or Cold: If not wearing suitable protection, make a STR + Physical skill check once every 10 minutes (DC 15 + 1 per previous check), taking 1d6 damage on each failed save.
Characters heal their level in HP every hour, or twice this with medical care. Once per session, a character can automatically heal themselves of half of their total HP as a "second wind."
Although all characters have a Force skill rank (except droids) only Knights can actually use Force powers. Using any Force power costs 4 HP (because it's tiring and wears you out to rely on it too much) and requires a skill check of 1d20 + Force skill + the applicable stat bonus (usually MND, but there could be a few exceptions at the GM's discretion.) Sometimes the DC that a character is trying to hit with his Force check is the equivalent of a Saving throw, and other times it might be an opposed Force check--even for Characters who cannot use Force powers themselves, they still have a Force skill rank which they can use in opposed Force checks. Other times, it's a static DC set by the GM.
For simplicity sake, there are only ten listed Force powers, which correspond to almost all of the Force action seen in the movies, tv show and video games. There may be other Force powers referred to obliquely, or in Expanded Universe material. There are no rules for them here, if so, but if desired, they can be homebrewed into the game with GM approval and involvement. Some powers listed here are traditionally considered "dark side" powers, but my interpretation of the Dark Side is that it's more of a plot device than anything else; i.e., it should be used as a roleplaying tool, not a mechanics tool--your GM will work with you on what the consequences are of using the Dark Side. Given the ability of characters in the Old Republic games to be Dark Side specific characters and still play quite successfully, there's no rule for "losing" your character to the Dark Side or anything like that. Again, that's all roleplaying.
When using the Force in combat, you must make your opposed skill check. If you lose the check, you still lose the hit points--it always costs 4 HP to use the Force, but the opponent suffers no ill effect. Some powers can be used against multiple targets. That's OK, but there is a -2 penalty to the Force skill check for each additional target beyond the first, and it costs 1 extra hit point per each additional target beyond the first. So, for example, attempting to Force Push five battle droids at once would incur a -8 penalty on the check (which must be made separately for each target) and would cost 8 HP regardless of the outcome.
- Force Push: Force + MND check vs. Physical + STR or DEX (whichever is better) of the target. Force Push inflicts 1d4 damage per Knight level, and knocks the opponent to the ground. The opponent suffers a -4 to AC until they can use a Move action to stand back up.
- Force Surge: Force + MND vs. static DC set by the GM. Useful for the amazing feats of speed and leaping common to Knights. Failure consequences depend on the degree of failure, i.e., if you just miss your check on a Jump, you don't reach your goal and may have to jump again. If you blow it by a larger margin, you may hurt yourself falling in the attempt. This one is very situational in terms of what the penalties for failure might be, although a good GM should use the source material as a guide and not be overly punitive.
- Battlemind: Force + MND check. For every 10 points made, the Knight gains a +1 to attack, damage and AC for the duration of the combat. For example, if a 7th level Knight with a +2 MND bonus rolls a 10 on a d20 (for a total roll of 19) he would gain +1 to attack, AC and damage, but take 4 points of damage, as normal. If he had rolled an 11, for a total of 20, he would gain a +2 to damage, attack and AC.
- Negate Energy: Force + MND check--DC equal amount of damage taken. By taking the standard 4 points of damage, the Knight can negate the damage from one energy source. Unlike with other Force powers, the Knight can Negate as many attacks per round as he has HP to spend on activating the power without any penalty for multiple targets. It also can be done passively when it is not the Knight's turn, but it does cost a combat action to use. If used passively in this manner, when the Knight gets his next turn, he can still move, but is considered to have already spent his other action on this Force power. Obviously, this is only desireable to do if the damage is higher than 4 points, and the Knight does not mind giving up his next action. This can also be used outside of combat to walk through fire, or an irradiated room, or something like that.
- Force Grip: "I find your lack of faith disturbing." A Force + MND check vs. a Physical + STR check. If successful, the target suffers 1d6 damage per Knight level.
- Force Lightning: Force + MND vs a DEX + Physical to dodge the attack, or a Force + MND to oppose, absorb or block the attack (for example, on your lightsaber blade.) The target of a successful check takes 1d6 damage per level of the attacker.
- Stun Droid: Force + MND vs. Physical + DEX or STR (whichever is better.) Treat this Force power as if it were an ion attack; droid targets which do not make their save are shut off.
- Mind Trick: Force + MND vs. Force + MND (even characters that cannot use Force powers, i.e., non-Knights, have a Force skill ranking that they can use to oppose Mind Tricks.) A simple opposed check in which the Knight can make a suggestion seem amazingly reasonable. The GM may impose, as with any skill check, situational modifiers may apply if the target thinks the suggestion is outrageous or over-the-top.
- Farseeing: Often a Force + MND against a static DC set by the GM to see a person or place in the past or present, or even glimpses of possible futures. The GM can also roll checks against this out of combat in secret to give the player clues or hints about things going on around them (such as sensing an old master or enemy nearby.)
- Telepathy: Force + MND against a static DC set by the GM to implant a message without speaking (and possibly across great distance). The message is usually short and fairly simple, and comes with no compulsion to act on it. Receptive minds may grant a circumstance bonus to the check (i.e., Luke trying to contact Leia so she can pick him up before he falls off the bottom of Cloud City) while resistant or unwilling minds may cause a penalty, at the GM's discretion.
At the bargain price of 4 HP per power use, Knights start out somewhat weak but become more powerful as levels progress. But, because I effectively cap the game at 10th level, the real runaway force prodigies, like Yoda or Sidious, may not really be recreatable without breaking the rules and going higher level, or perhaps giving them a unique Affinity to using the Force that reduces their HP cost from 4 to 2. I don't recommend that for player characters, unless you desire a campaign in which Knights are much more dominant.