Which type of reward can directly improve a player's chances in battles?

The correct answer is cards, as they directly influence a player's capabilities and strategies in battles. In the context of a game like Riftbound, cards often represent different abilities, spells, or units that players can utilize during combat. By acquiring and using cards effectively, players can enhance their tactical options, deploy powerful abilities, or summon formidable creatures, thereby increasing their chances of winning battles.

In contrast, while achievements, experience points, and resources contribute to a player's overall progression and development in the game, they do not provide immediate, direct enhancements to battle capabilities. Achievements may unlock certain rewards or signify milestones but do not provide battle advantages. Experience points are typically used to level up or unlock new features, which can indirectly improve a player's effectiveness but do not immediately change the dynamics of a specific battle. Resources are crucial for gameplay mechanics, such as card purchases or upgrades, but they also do not directly influence the outcome of battles on their own without being tied to action cards in play.