Which one(s) you focus most on improving will, of course, depend on your civilization, leader, and overall strategy. You never want to have the lowest Science output your development will be slowed, you'll be easy prey for warmongers, and if even if you survive, you'll eventually lose diplomatic influence (since other players will have less trouble completing quests for city-states and you won't have a strong enough military to protect your interests). You'll need Production to quickly construct buildings and wonders and train units.

Improve your cities' yields: You'll need Food to grow your Population, work more hexes, and build more Districts in your cities.

Always keep some on hand for emergencies.

Watch your treasury: Gold can be used to purchase units or levy them from city-states, which will give you a much stronger defense and more options in wartime.It's also advisable to ask for friendship with players of whom you're suspicious, which will prevent them from declaring or joining wars against you. You should also make sure you have a large enough military to defend yourself on all fronts - if you use your entire army and navy to attack your neighbor, another opponent might launch an attack on you while your territory is undefended. This ends the deal and leaves you unable to purchase units, while giving your opponent lots of Gold to spend. A cunning player may, for example, propose that you give them all the Gold in your treasury in exchange for most of their strategic and luxury resources, only to declare war on you the following turn.

Warmongers are prevalent online, and are way smarter than AI opponents. Never trust anyone: Don't expect any pity, especially from strangers.The game host will decide every setting, including the map, the speed, the starting era, and which players, if any, will be on teams. Multiplayer allows you to play Civilization VI with or against friends and strangers (and possibly AI opponents).

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