Gold is used to fast surrender or ahead of schedule to win. Press “Options” to paused game and see “Surrender” button (30 gold) and “End of time” button (сertain conditions and 100 gold).
For buy upgrade: Click on unit, click on shard to attach this shard to selected unit and see upgrade info (hohour costs is different for each race). Press "get" to buy upgrade if you have enough of honour points.
Unlocked passwords will be useful to you at repeated game or game for another race.
You may dont remember it if you want.
no need buy all upgrades or build all towers. you may chose you way:
build 1-2 tower and upgrade it, or build towers to protect only one side. if you wizard always shot - dont buy turbomeditation, buy upgrade for towers to get power instead.
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