What do 「し」and「あった」mean in this sentence?

Question

I'm a beginner Japanese student using Yu-Gi-Oh subtitles translations with the original in Japanese. I don't understand explanations in Japanese mostly, or it takes me a long (believe me, long) time to understand them yet. Well, I've spent a good - I mean good - time researching about the following sentence. Only I couldn`t understand two words of it. The rest I could painstakingly happily understand very well thanks to dictionaries, web and patience - yay. So, could somebody give me a hand? Here it is:

古代｛こだい｝におけるゲームは人間｛にんげん｝や王｛おう｝の未来｛みらい｝を予言｛よげん｝し運命｛うんめい｝を決｛き｝める魔術的｛まじゅつてき｝な儀式｛ぎしき｝であった。

Something I thought was that maybe the 「し」 worked as a sort of conjunction to connect both sentences. 「あった」, I thought maybe was a sort of collocation with the idea of "They met the decicions of their fate through the magical ritual".

Thanks in advance for the help.

Answer 1

Here し is the pre-masu form of する, and equivalent to a slightly more formal form of "して". Here is another example of this usage:

彼はりんごを手に取り、食べ始めた。

He took the apple into his hand and began to eat it.

In this sentence 取り can be replaced with 取って, though the former sounds a bit more formal to me.

For the second question、であった is simply the past tense of である, which is a more formal/classical version of です. It simply means "was" in this sentence.

Here is my rough cut at a (slightly non-literal) translation of your sentence.

In ancient times, games were magical rituals to make predictions about the future of people, such as kings.

Answer 2

し is 連用形 form of する.It joins the two sentences here.
であった is past form of copula である.

So the translated sentence will be like
"The games in ancient times were magical rituals which involved predicting the future of a person or king and deciding their fate."