Players keeping in character (especially when it can put them at a disadvantage) and actively posting, can earn RP points. You may spend these to affect the game in some basic ways. The most prominent of uses is using these to buy captain, crew and ship traits, or buying heroes. Bad roleplaying (such as meta gaming, or being a jerk in general) and inactivity can likewise earn you NRP, which can inflict negative traits, cause plagues, etc.
Captain Traits (cost 1 RP can only have 1/captain)
Tactical Genius: At the start of each battle, you may choose a non-weapon, non-hull system the ship has and grant it a +1 bonus to its value for that battle.
Shade: +1 to the ship's stealth value, and the craft receives a +1 bonus to damage value during a surprise wave but the captain will not fight to the death, looking to retreat when reduced to 1/2 or less hull value.
Patient Hunter: +1 to the ship's sensor value, if the captain is actively searching for a craft, the ship's sensor values are at an additional +2.
Undying Loyalty: +1 to weapon damage values, and +1 to boarding strength
Resourceful: Reduce penalties to engine, warp and attack values by up to 2 each (note that this does not negate value penalties from your own traits and effects, simply those generated by your foes and the environment).
Explorer: +1 to the ship's warp value and +1 to it's sensor value when using them for non-combat actions.
Ruthless: +2 to weapon damage values, but must attack the largest and/or most powerful target in the battle, must always attack pass 1 if able and will fight to the death.
Crew Traits (Cost 1 RP can only have 1/crew)
Miracle Workers: Ship may repair for 1/2 normal cost.
Fearless: Ship inflicts 1 extra damage against and takes one less damage from larger craft and defenses.
Hardened: The ship has +1 to its base boarding strength
Patriots: The ship's crew is immune to effects that would otherwise demoralize them.
Ship Traits (Cost 1 RP can only have 1/ship)
Enduring: +2 Hull Value
Scourge of the (alien race): +1 damage values against and takes 1 less dmg from a certain race.
*Note that you must have encountered and battled the race before with the ship to gain this trait.
Advanced Damage Control: Negates ongoing damage from weapon traits, and reduces the bonus damage a weapon would gain from a trait or ability against your hull by 1.
Monstrous/Unmanned Traits (Cost 1 RP, limit 1/ship)
Relentless: When this craft/creature is at 1/2 or less hull value, it gains a +1 bonus to engine and weapon damage values.
Feared: This craft/creature has earned a fearsome reputation, and terrible stories follow in its wake. Enemy ships engaged with this craft must target this creature/ship with at least half of their damage each wave. Each enemy ship in the battle has -1 to all non weapon, non hull, non shield systems. If this craft/creature attacks a world, it adds 1 to the fleet's planetary attack value.
Lurker: This craft/creature is better at sneaking than most ships of its size, it is treated as though it were up to 2 sizes smaller in terms of stealth and sensors (note this can only reduce a craft to a virtual size of 1 in this way).
Heroes provide bonuses to worlds, stations and possibly fleets. Thier RP cost varies according to strength. Note that if these heroes are upon a world, ship or station that is captured or destroyed, there is a chance you may lose them (of course there's also a chance they may survive!). If an alien race captures them, they may either execute them or hold them for ransom, etc.
Influencial Leader: Assign to a world or station, improves infrastructure cap there by 3 (for stations this applies to maximum infrastructure cap as well) and increases the boarding strength/planetary defense value of that world or station by 1.
RP Cost: 1
War Hero: Assign to a station or world, increases boarding strength/planetary defense value there by 3.
RP Cost: 1
Fleet Admiral: Assign to the largest ship within a fleet (other than monstrous, unmanned or size 0 craft). While the admiral is alive and their ship is able to take actions, the entire fleet receives a +1 bonus to their weapon damage values and each take 1 less damage from all attacks during the first wave of battle.
RP Cost: 2
Legendary General: If assigned to a world, that world has a +4 bonus to its planetary defense strength. If assigned to a ship in a fleet that is invading a world, you may reduce the defender's strength by 3.
RP Cost: 2
Prodigy Engineer/Mystic: Assign to a world or station, that location has its production and construction values each increased by 3.
RP Cost: 2
You may choose to spend RP to affect anything with random chance (that has not already been predetermined), if used in this manner, you may spend 1 RP to cause such an effect to always come out favorably.