Legal matters aside, this is something that has happened to me in the past, several times in fact.
I've suggested partnering on several occasions, and I'll list the outcomes I've seen:
"Project A: an unambitious retro turn-based RPG"
When working on Project A (a 2 men somewhat dedicated team) we've stumbled accross a community with like-minded goals.
Initially, we've approached them, pitchting our idea, open for discussion or debate, simply so we could get an appreciation from them, perhaps they could shed a light on what we did right/wrong and help us progress, or perhaps they could embrace the idea and merge it with them.
Our ideas were rejected (and eventually 'stolen'). We were initially offered to work as programmers-for-hire on their project, minus the creative input, which, obviously, was of no interest to us.
Lesson learned: Some established team have set themselves in a hierarchy that cannot adapt to changes. The team we had approached had such a rigid foundation: they liked our ideas, but by principle, the ones holding the reigns of creativity did not want to integrate new members. That said, they recognized our value as programmers, because, quite frankly, they had too few (they were one of these teams were a lot of people put themselves in a position of power as acting ideas-men, but hadn't convinced enough developers to hop aboard). In the end, they took our ideas for themselves, and continued on them. I won't name names, but this project is still active to this day, and its been years now...
"Project B: 3D FPS/RPG Hybrid"
While working on my own take on the fps/rpg genre (much influenced by the original Deus Ex: The Conspiracy), I've met with a 'project lead' that had a similar project in mind.
The project lead was pretty much a producer from my understanding at this stage. He had a large team ready to work (programmers, artists) but was lacking creative input.
After initial contact, he has put me in a position where I would flesh out initial story elements, art descriptions, general gameplay, etc. It was a pretty big deal, and I was interested because, while he had difinitely different opinions than me, and would insist on overseeing everything and ask for changes, I had the opportunity to do what I do best with the support of an entire team.
Pre-production began very quickly, even as design continued to evolve, and we were off to a pretty good start. It seemed like our 'teams' had merged wonderfully.
A few weeks down the road, the project lead was harder to grab a hold of, which was peculiar, but still not alarming (we all get busy with real life).
Then, things started to take a wrong turn and I realized only too late what was going on:
Artists eventually came to me discretely wondering when they'd get paid... With the project lead's sudden disappearance, it appears they had no one to turn to but me, but I hadn't planned on investing into this one particular project. I was under the impression the project lead had taken the necessary legal steps (I hadn't ask for compensation myself at that time, thus I did not know it wasn't the case).
It turned out the project was like a plane with no thrusters.
When the project died, I was left with the original documentation I had produced before merging, knowing I probably couldn't use it anymore now that it was mixed with this project I had boarded. While defunct, it smelled of lawsuit and everything, and I'd rather not associate with a project that could die at the end because of former employees taking action against the project lead.
I walked away...
I have a few others, but I'd rather not go on a wall-of-text rant.
Here are a few conclusions I've come to regarding these situations:
Major issue here is the authority clash, in other words, who is in charge. When you suggest to merge, the hierarchy of the two teams will go through a tough time. If the team you are contacting had a cool thing going on with minor issues to solve, they may not be interested in making drastic changes to the project's structure. Its like if you're running a slightly undermanned business, say, a grocery store missing one cashier... to get the missing cashier, will you suggest to merge with another grocery line? Probably not... At least, not on that count.
A byproduct of this issue is, who will be in the topmost creative position. Perhaps the team you are willing to merge with has a person that has secured a position of creative input. To this person, this position may be more important than the final result even. They may be more interested in overseeing their idea from start to finish than to collaborate. They have no way of knowing whether they do it for best or worst, but they like their position and see no reason to jeopardize this. They know their idea rocks, they know 'they rock' and while your idea may rock too, they don't know if they can totally trust you making the best out of both (perhaps you're just trying to impose your vision after all). Its a big ego battle that usually plays on the creative level, but you might see this at other levels too (art, even technology).
I'm not saying this is always the case, or always on both sides, but its a variable that plays into this.
Edited by Orymus3, 10 February 2013 - 12:03 PM.