If you are a player that just recently picked up Valorant or doesn't have Valorant as one of their main games, "force buy", "eco" or "full save" might not be terms you're familiar with.
Riot has taken the age-old formula of purchasing guns, armour and utility from Counter-Strike and inserted it into Valorant . Valorant is a tactical shooter that has you paying for more than just skins, thankfully not with real money.
Every round, you get the money that you can spend on armour, guns and abilities. Everyone starts off with 800 credits. Losing results in less money for the next round. Winning results in a monetary bonus based on the number of kills you've made as well as whether or not the Spike has been planted/defused.
A force buy is a round where you do not have enough money to purchase a full loadout (Heavy shield, all abilities and a Phantom/Vandal) but you do have enough money for an SMG/Marshal paired with a light shield.
Eco rounds are throwaway rounds that are there to reset the teams economy and give them a chance at retaking the lead, winning these rounds is an additional bonus. In an eco round you will buy a pistol, and a light shield only if you will be left with a minimum of 2000 credits in your bank, otherwise full save (don't purchase any shields or weapons).
Eco rounds follow up after a failed force buy. If an eco round results in a loss, try forfeiting (jk). If an eco round results in a loss and the team still doesn't have enough money, the next course of action is a full save.
Once the match starts, the first round is crucial. If the first round results in a win, the second round can be either an eco or force buy, depending on your preferences.
If the first round results in a loss, the team should full save or eco the next round in order for their economy to balance itself out for round 3. Force buys should take place whenever the team starts losing the advantage, eco or full save rounds should happen if your team loses a force buy.
Forcing more than one force buy round will keep your team at a disadvantage by spreading out your economy over several rounds where winning is less likely.