This page gives an introduction for new players on the basic strategies that give you better chances at winning games.
 Getting started
It's a good idea to play the first three single-player levels before jumping into multi-player. These will ensure you understand the basic idea behind bonuses and basic combat, as these are necessary prerequisites to playing Warzone.
In games with lots of players, it's generally a good idea to try to avoid getting into a lot of battles with other players. If two players are fighting each other, and a third is growing unencumbered, the third player tends to win more often since the first two are depleting their armies against each other.
Remember, fighting between two players weakens both of them. Be careful who you pick a fight with - even if you end up winning the war, you may just be opening yourself up for conquest by an even stronger neighbor.
Of course, you can't win without fighting at all. Therefore, it's necessary to find a balance. The best wars are ones that you can win quickly, whereas the worst ones are wars that you either lose or go on for a long time.
 Heads-up games
Games with only two entities (1v1s, 2v2s, etc.) require different strategy than free-for-all games. In these games, breaking an opponent's bonus is just as good as (sometimes better than) taking a bonus yourself. Therefore, going on the offensive is usually a good decision.