I have looked for some words in Scrabblewordfinder and Collins Dictionary. I found that in every pair like metre–meter, colour–color, defence–defense and so on, both words in each pair are usually considered legal and acceptable. So, according to both dictionaries, one can play either METRE or METER etc.
However, if a player on each his/her turn just always chooses randomly between BrE and AmE spelling, it is pretty weird. At least for me. It shows that the player is very inconsistent.
So my question is: if I am playing a game of Scrabble in English (but I am not an Englishman or an American, and I am not playing in United Kingdom or United States), which spelling should I prefer, British or American? Are there any common preferences or traditions? Thanks.