It's been a long time since I've GMed a game. But recently I have officially gotten into it again. I've modified Savage Worlds vehicle combat to make a space game. I'm three sessions in, but haven't tested the space combat, as the players are not familiar with Savage Worlds yet, therefore, I am trying to introduce them to the various systems session by session.
The first session was character creation, I introduced the world, the expectations, the disclaimers that things may change due to the experimental nature of the game, and the coming up with rules for things they want their characters to do, but don't have specific or particularly accurate rules for. Mainly this was an OCD engineer and a few other hindrances. Mainly as basic versions may not be hindering enough or perhaps even too hindering.
The second session was to introduce skill checks and to get the players their ship. This used a series of skill checks to scan some information, gather some hard to find supplies, gamble with the rabble on board, and then get into the ship. The ship itself was mainly random, they got some bonus rolls for some earlier skill checks, and had a chance to get less rolls if they did poorly on said skill checks. In the end, the party was, believe it or not, vocally disappointed the ship wasn't more of a wreck. I don't know if this is the case because I listed off a few bonuses they were getting, or if it was because they don't understand how many awesome things there are out there. Finishing up, they chose their destination, then headed off to the next station. After this there were complaints about no combat or 'great escape' with the ship. But I wanted to put off ship combat to it's own period of time.
The third session was introducing some person to person combat. I tried hard to keep the party from splitting, but even as I was going I saw it happening. I really didn't want it to happen, but so be it. There was a lot of social exchanges rather than fighting at first, but then at the end as things were wrapping up, the players actions caught up with them and there was a shootout. It was the most fail shootout ever, the players just couldn't roll for shit. On the bright side, neither could the opponents. I think I also tuned the enemies defenses a bit too high, so I'm going to drop that down a hair next time. This was person to person, which isn't homebrew at all, but it's just inexperience with GMing the system I think.
The fourth session is coming up, I have plans, but right now things are still in the works. Waiting on next Friday hopefully when things come together.
Outside the game I spend most of my time figuring out how best to display the space combat, and efficiently convey all the data from it. I'm hoping things go well when the time comes.