Voyager and V2 use the D&D 3.5 Rules with the following modifications:

DMG p.25: Automatic Hits and Misses

An attack roll of “1” is not an automatic miss. It is treated as a -10 for purposes of calculating the AC hit. Similarly, an attack roll of “20” is not an automatic hit. It is treated as a 30. Additional: This rule has been extended to cover ALL d20 rolls.

DMG p.36: Power Components

Special, rare ingredients can be substituted for XP for preparation of certain powerful spells.

Losing a level costs XP, not necessarily a full level

When a character dies, instead of his/her XP being placed at the midway point of the previous level, they will lose 500 XP for each level below their current. As with the standard rule, first level characters lose 2 points of CON. The intent of this rule is to add consistency to an otherwise painful rule. It no longer punishes characters who are close to a new level when they die.

Example: Pavo is an 8th level Dwarven Fighter killed by a determined Frost Giant. Instead of being placed at 24,500 XP (midway between 7th and 8th), he will instead lose 3,500 XP (500 * (his level at death - 1)). If he was at the bottom of 8th level (28,000 XP), he would end up at the same point as the old rule (24,500 XP). However, if he was near the top of 8th level, he would remain 8th level.

Death does not come as fast

• A person is Disabled when they have between 0 and -F (inclusive) hit points (where F is the person's Total Fort Save).
• While disabled, any standard (or strenuous) action inflicts 1d4 points of damage.
• A person is Dying when they have between -(F+1) and -(F+10) (inclusive) hit points.
• A person is Dead when they have -(F+11) (or lower) hit points.

Example: Pavo (F=12) would become disabled if his hit points dropped anywhere between 0 and -12. If he ends up at the midpoint of this range (-6 hp), he'd be able to execute (on average) 2 standard actions without entering the dying condition.

The Nature of Evil

(need succint definition of my moral compass here)

Languages

Just as described in the PHB, each character starts out with Common, their racial language(s), and a number of bonus languages equal to their INT modifier. Each language can be spoken fluently with no chance of significant misunderstanding.

However, the Common tongue is not the all-encompasing language the rules make it out to be. Instead, it is a rather limited trader's tongue. Simple conversation is possible, with special emphasis on the words and concepts relating to barter. However, advanced conversation is difficult and, in many cases, impossible. Additionally, many monsters and wilderness races do not speak Common in any useful way.

However, speaking without a common language is still possible, depending on the similarity of the languages known. Any two languages have points of similarity and with a successful Speak Languages roll, conversation is possible.