Alliances Criteria for Beginners

Friendly isn't enough, I believe you need to be Close.

Yes, I have the same problem! And how "close" is close? I mean, what does it take to form an alliance? And I have not really understood what I meant to do with those "influence" sliders in the chatting room with the aliens? What does it mean when I actually give influence to the alien? What does it mean when the alien too has a slider for influence for deciding the amount to be given? What are they used for?

The influence you can trade on the diplomacy screen has nothing to do with this (well, almost nothing - close enough to ignore).

What you need is to get your relations to Close. Do this by checking your information on the target civ; there is one screen in the foreign relations tab that gives you a breakdown of how that civ sees you and gives you a list of + and - factors that are affecting this. Check the list, and try to eliminate as many of the - factors as possible. To gain + factors, you can send freighters their way, give them econ or research treaties, build up your military, have the same ethical alignment, etc. Giving gifts can also help (that's the one way influence points can be used to affect this).

All of the preceding can only get your relations up to Friendly. The jump to Close has a random chance of occurring each turn you hold your relations at Friendly, so just keep checking every few turns. Nothing you can do will affect that jump.

Once you get the Close relation, BOTH civs need to have the Alliance tech to form an alliance. If they don't have it, sell it to them.

The influence points in the trade screen are the accumulated points your (and their) civ have generated since the last UP meeting. When you give them influence points, you are trading away a tiny bit of your voting power in the next UP vote. It's nearly impossible to trade enough of these points to affect the outcome of a UP vote, but they can be sold for cash in a pinch. Just remember that the AIs pay less for points when you offer more points at a time. You will get more cash selling 100 at a time than 1000, and 10,000 will get you very little. What the AI is willing to pay is also related to how much cash they have; getting their last 100bc is expensive and hardly worth your time.

Thank you for the advice, it would have taken me a long time to figure that out on my own.  As it turned out, I had established a "Close" relation with a different alien race and didn't know what that meant.  So, basically, if you happen to achieve a "Close" relation with an alien race, jump on the chance to make an ally of them!

Not necessarily. You still need to evaluate whether the alliance is worthwhile to you. You can easily get an alliance with someone and have several others declare war on them the next turn - when that happens, you either have to jump in to defend your ally or take a permanent - to your relations with ALL civs as "untrustworthy".

OK, Thanks for your replies and help! I

I have another question. How do I break my alliance with a minor race? I need to do this because I can't attack him unless I first break off my alliance with him. Must be a simple way of doing it that I have overlooked?

IIRC you can't - at least not directly. You have to pay someone to attack them, then not honor the alliance. Just be aware you will take the diplomacy hit for doing so.

OK. Thanks. Good idea and the only one!

If an alien race responds to my request for an alliance with "That will never happen", do I take that at face value and give up any hope of ever forming an alliance with them?  Or, should I keep trying each time I improve my Diplomacy factor?  Are there other factors that would prevent them from accepting my alliance request?

It means they don't consider it valuable enough.  Add more things to your side of the diplomacy screen until it goes green (it should, eventually, if you have the option).

You might check on your relation +/- factors under foreign relations and see what's making them feel that way, though.