I am looking for a creative mana generation idea for a 3rd person videogame prototype I am developing in UE4 for a class assignment. The prototype is based on a trading card game that has been converted to your generic third person videogame with story mode but without turn-based combat. Specifically, I am working on the combat system and other general programming for this prototype. For combat, I have chosen to implement animated combat cards (Melee, Spell, etc.) that move around on the players HUD and show the attack type, casting cost if needed, its effect, and how much damage it deals when the player presses the attack button. However, I am having a difficult time with deciding how the character will generate mana to cast certain cards that require mana.

Some obvious routes for mana generation would be to automatically regenerate mana over time, have enemies drop mana orbs/cards (obtained through free attacks), generate mana from a character ability, charge up mana by holding a button that delays the player from attacking or playing cards, automatically insert mana cards into deck based on player level, or eliminate mana altogether with timed cooldowns for casting spells. I believe because the prototype is based on a trading card game that involves mana you obtain by drawing from a deck, that it should include mana and a creative way to earn or generate it. However, I don't want mana generation to be too easy, complicated, or simply a copy of the trading card game being converted. For example, Pokemon gets around mana generation with power points for attacks in most of their videogames, but is turn based and requires you to use an item or heal your character at a Pokemon Center to restore. As you can see there are many mana generation methods and I am having a hard time finding an original idea that fits.

I am looking for any input or creative mana generation ideas that I could implement. Thanks.

How does the player draw cards, before they “move around on the players HUD”? At a constant rate? When the player does a specific action to draw them? Shortly after using another card, with a possibly variable cooldown interval?

By default, obtaining mana should be similar to obtaining useful cards, particularly in the case of an adaptation of a game where mana and payloads come from different card types in the same deck (or maybe from choosing to spend the same cards as a power source or for their effect, a very common TCG design pattern).

@LorenzoGatti Nothing is set in stone just yet as I am currently working on player states and animations, so any part of the concept can be changed. Most likely the combat system wont be perfect from the start and will require adjusting. However, I need to stick to a general concept once I have it. To meet my time limit for this prototype, I will be working with a limited amount of generic cards (Combat (Melee, range, magic), spells, and summon).

To answer your question, the idea was to draw cards into the players hand at a constant rate (Condition: after a playing a card in your hand, summoned creature from card in hand dies, or spell that allows you to draw extra). I have not planned much of an interval when using melee combat cards, only limiting the player to the time for combat animation. Cards can be used in unison to a certain limit to allow attack combinations. Cards in hand are assembled like a stack where order doesn't matter and animate on HUD when traversing through your hand or playing a card (removed from hand). Decks are managed in pause menu (Only accessible when out of combat), and new cards can be obtained from NPC drops, winning a player battle, or leveling up. Some enemies can cause you to discard cards with special abilities reducing the amount of cards in hand until you run out. If you run out of cards in hand, you can no longer draw cards by attacking or casting spells and are forced to reshuffle (time interval with player animation). When you run out of cards in your deck and can no longer play spells in your hand that require mana, the graveyard is shuffled, returned to deck, and the player draws until starting hand size is reached. Summoned creatures take the place as a used card in your hand until they die and then is discarded into graveyard, although you can use/draw other cards during this time. Certain spells or effects can change the number of creatures in play and don't use up hand size. My initial idea was to clear mana and cards in hand when out of combat, forcing you to use melee attacks that don't require mana to obtain it. I was considering separating cards drawn that require mana on the other side of the screen but still effect hand size.

If you have played Kingdom Hearts: Chain of Memories, the concept is somewhat similar to what I'm looking for. However, there are a vast amount of differences from what I am trying to implement. For example, spells in the game did not require mana. Deck card limit was based on card points used to give value to different cards. Hand size and reset time interval for hand changes based upon how many times you have reset your hand by holding a button for time interval. Everything resets once you are no longer in combat. The concept I am trying to implement could also be somewhat compared to playing a commander game in MTG where your commander is your player character that you start with (Doesn't require mana) but contains free and paid attacks and/or a static ability used to obtain mana (Still trying to figure the mana part out), and can only generate mana of the commanders color.