This is a rough idea for a card game, mostly influenced by Magic: The Gathering.
There are five types of cards: Warriors, Spells, Forts, Artifacts and Equipment.
These cards are your troops. They attack enemy forts or invading warriors in the Attack phase. Each warrior has it’s own Attack, Defense, and Will. Attack is how much damage the warrior does to opposing warriors. Defense is how much damage a warrior can sustain. Will is how strong the spells the warrior can cast. You play these cards from your hand during your Reinforcement Phase at the beginning of your turn, but you may only have one warrior per Fort (and one extra for your Capital) or six warriors maximum. When a warrior is beaten, it goes to the Graveyard pile.
At any time, you may expend any of your Warriors’ will points to cast a Spell from your hand. The will points are restored during the Reinforcement Phase, but if they can afford it you may cast multiple Spells. If the Warrior is the same Element as the Spell, you get a discount of two Will, but only on one spell per Warrior per turn. Spells can damage warriors, weaken forts or remove cards, etc.
These are what you fight over. Each fort allows one warrior each, except the Capital. Everyone begins with a Capital, which is not a card but is represented by whatever you have handy – a mug, a shoelace – be creative. Capitals allow two warriors, (only one if it’s not your original capital), but don’t have any extra benefits. Extra fort cards are in your deck. You can have a maximum of four extra Fort cards per deck. After playing a Fort card during your Reinforcement turn, you can’t play a fort’s extra warrior until your next reinforcement phase. If a warrior attacks a fort, and it is not defended by the opposing player, you gain control of it in your next attack phase; the invading Warrior cannot attack this turn, but can defend. (Remember to give the fort back after you win!)
Artifacts and Equipment
Artifacts are cards that apply bonuses to individual forts (including your capital), while equipment applies bonuses to individual warriors. You may only have one per warrior/fort. These can only be moved during the reinforcement phase. If the warrior is killed, or the fort is captured, you must move the equipment/artifact to the graveyard.
During this phase, all your warriors’ Defense/Will returns to normal, and you draw a card for each of your own forts you control (maximum of three). You may play or move equipment and artifacts around, and you may play/return warriors from/to your hand. You cannot return a warrior to your hand if it has casted a spell this turn. You may also play one fort per turn. Invading warriors are not healed.
You may then choose which of your warriors will attack which forts; however those warriors can’t return to defend your forts in the same turn. If your warrior wins the fight or is not defended against, they start capturing the fort. If your warrior is not stopped before it’s next turn, you take control of the fort. (Remember to give the fort back after you win!) During the attack phase, you may also attack invaders to stop them capturing your fort.
If your fort is attacked during an enemy’s turn, you may choose one available warrior to defend it. Some forts give bonuses to defenders, but not invaders.
The graveyard is where your soldiers go when they die, as well as equipment/artifacts. Some cards can bring one of these back, though!
When you cast a spell from your hand, or when you run out of room in your hand, you put the card in the discard pile. If you run out of cards in your deck, you can shuffle your discard pile and form a new deck with it. Don’t confuse it with your graveyard!
Every turn during your reinforcement phase, you may draw 1-3 cards – one for each of your own forts you control. You may only have six cards in your hand; you must discard any extras, but you can choose what you discard.
You win when your enemies have no forts or capitals.