So, I was thinking about a spaceship game. I started thinking - instead of abandoning ships as you buy your way up the line, how about if you could just replace large chunks of it? There's never a feeling of abandoning the ship for something bigger - you're just growing the ship incrementally. A new saucer section, a new spine, a new crew frame, etc.
Then I realized this was essentially the same as a party-based RPG. The various big hunks of ship are party members, and the tweaking you do within each section is similar to equipping and skill-leveling.
So I began to think about cross-pollination. What mechanics could be taken from each side to create a fresh feel for the other side?
The first thing I thought of is that a starship's pieces do not act independently. Normally, you control all the pieces with a central command system that either simply assumes each system performs at peak or allows you to distribute points of energy between them.
Imagine if you had a party-based RPG - let's say, one where the party members are AI-controlled. Like Mass Effect, minus Shepard. Imagine if you had some measure of energy. Call it "command points" or "point points". Assigning these on the fly changes which characters take the lead, which characters use special abilities and limited resources, and so on. (You could also do this in a classic JRPG game, but it would be a bit clunkier.)
The idea is that you don't have a lot of time to give orders. There's no pausing. You can indicate locations (an attack flag, a retreat flag, etc) and alter the command point configuration, but the battle itself progresses quite fast, so choosing individual skills and aiming them would be too slow.
One of the big effects this would have is that the party members could be much more specialized. In fact, you could have much larger parties with much more specialized participants. The space elf doesn't charge forward when you give him command points - he heals and buffs. He takes potshots at low command levels, but if you want a charge, give the command points to the space orc.
Taking the party as a cohesive unit could be interesting.
Going the other way, the ship can also take on elements of the party mechanic system. In the bluntest way imaginable, you could just give each section of the ship its own commands in each turn of combat. If you do this, then each part of the ship has to have a diverse baseline of capability plus some specialties. This would be an interesting challenge from a design standpoint, but it could end up being even more interesting than as a party mechanic because a ship has crew. You could funnel crew between the various sections to enhance their capabilities, boost their repair rate, or avoid losing too many crew to a nasty missile volley.
Speaking of damage, what if we applied ship-style damage to RPGs?
Right now, RPGs basically ignore damage. If you're above 0 health, you're fine. But what if we introduced damage - if a character is wounded, they become less capable, at least until they patch themselves up.
The problem with this approach is that it is a positive feedback situation, where once you start getting damaged, you're in trouble. But we could balance this out by making all the characters gain energy (not health) when a character is damaged. This means that the other characters would be able to act at a much higher level when their teammates are injured. Depending on balancing, this could even mean that the party getting injured actually makes the team stronger, at least for this fight.
Of course, once you're out of combat, that adrenaline wears off and you're still injured. Now you've got to think about whether you can just bull through, or whether you need to back off, stealth a bit, recover a bit. Switch out the injured party member with a reserve...
Cross-pollination is fun.