I've been kicking around an idea for a fantasy-themed pseudo-coop tower defense game, and could use some help coming up with ways to improve synergy and make engine-building more interesting.
The overarching theme is that players are the minions of the Dark God whose resurrection is at hand. The Heroes of the land are trying to prevent it, and the players must stop them using Monsters, Spells, and Relics. Killing Heroes earns players Soul Points tokens which can be spent to purchase more Monsters and Relics, but whomever has the most Soul Points at the end of the game wins. Players must choose to either spend Soul Points and improve their engine or horde them to try and win.
The game takes place on a tile-based board, with entry points for Heroes and the Altar (i.e. the "tower" players must defend) at the center. There are 3 types of cards: Hero cards (representing the heroes players must kill), Spell cards (single-use effects played from a player's hand that mostly affect the board state, such as "move any Monster or Hero 1 space" or "rotate any tile"), and Boon cards (Monsters and Relics that players can purchase using Soul Points). Purchased Monsters are set in card stands and placed on the Altar tile, which players must move around the board and attack Heroes. Purchased Relics cards are placed face up in front of the player and provide constant benefits, such as drawing a Spell card at the start of a round or making all of your Monsters slightly stronger.
Monster and Heroes have 3 stats: Strength (combat ability), Speed (how many spaces they move), and Health (how much damage they take before they die).
A game round consists of 2 Phases: the Minion (Player) Phase and the Hero Phase.
At the start of the Minion Phase, if a player has more Monsters than Activation Tokens, they gain Activation tokens until it is equal to the number Monsters they control. Activation Tokens are used to move Monsters and use some of their special abilities. Players take turns of 2 Actions each, where an Action is one of the following:
- Play a Spell card from their hand
- Spend an Activation Token to activate (move and attack) a Monster they control
- Perform an Action ability stated on a Boon card (many of which require spending Activation tokens, or can only be used once per game round)
- Sacrifice Soul Point tokens to acquire a Monster or Relic from some common pool. Players can optionally sacrifice their own Boon and Spell cards for more Soul Points, but those can only be used to acquire Boons and do not count towards winning the game.
- End their round. Their turn ends immediately and can take no more turns for the rest of the round, but if they are not the last player to do so, they may draw a Spell card from the deck.
Once all players choose to end their round, if goes to the Hero Phase, where each Hero on the board tries to move closer to the Altar tile in the center and fight monsters along the way. If any Hero reaches the Altar tile, the game ends and everyone loses. If a Hero is killed during the Minion Phase, they are replaced with a new Hero at the end of the Hero Phase.
Combat is very simple, consisting of an Attacker and a Defender. Each side takes their Strength, adds any bonuses, and rolls a D6. If the Attacker has a higher total, the Defender takes 1 damage. Otherwise, nothing happens. Heroes and Monsters may have context-specific bonuses on their cards, and gain a +1 bonus for each friendly piece on the same space. All Heroes are friendly with each other, and all Monsters are friendly with each other, regardless of who controls them (making it easy for players to horn in on each other's kills). Initially Monsters can only attack Heroes, but there could be a cut-throat variant where Monsters can attack each other and only give each other bonuses if their controlling player allows it.
That's pretty much the entire game. I'm now trying to think of ways for players to build their engines. The main part of the game is in the combat, since players need to kill Heroes to get Soul Point tokens, which means acquiring Monsters and making them stronger. Spell cards can help move Heroes and Monsters into position, and Relics have a variety of secondary effects.
For engine-building, I figure there could be things like Relics and Monsters that let you draw extra Spell cards or increase your hand limit, and Monsters that become stronger with more Spell cards or Relics that increase the potency of Spells. Another idea are Monsters that become more powerful when the player has more Activation Tokens, and Monsters/Spells/Relics that increase the number a player has.
I had originally planned on there being a few "types" of Monsters, where each type has a particular engine-building theme to it. Heroes and Monsters could also have abilities based on those types (e.g. Hero gets +1 Strength when fighting Undead Monsters, or a Monster gains +1 Strength for each Arcane Monster you control).
Any other ideas?
That's interesting.
For starters, I wasn't even thinking of the board as some overworld map; I thought of it as a crypt/labryinth that Heroes must navigate. On the Hero Phase, each Hero would take the shortest path to the Altar tile, and players could delay their arrival by moving the Hero or re-arranging the tiles and put them on a different path. Granted, using an Overworld map could work effectively the same way, where the "walls" are actually impassable terrain, such as mountains or dense forest of something. That could open up abilities based on the particular terrain represented by a tile (desert vs plains vs forest, etc.).
I really like the idea that just having a Hero on the Altar tile doesn't end the game. Maybe having a number of Heroes equal to the number of players (which is at least 2) does end it. This way when one Hero reaches the Altar, there's massive pressure to get rid of them, but since you only need Heroes on the tile to lose, players can't simply stack all of their Monsters on that tile to prevent a loss. I had already intended to increase the number of Heroes based on the number of players, so this fits nicely.
I had toyed around with the idea of multiple Heroes from the same origin at the same time. I had also planned on Heroes of different levels, where higher levels mean stronger Heroes but bigger rewards. Maybe all Heroes are level 1 to being with, but as soon as a Hero makes it onto the Altar, it summons the next higher level of Hero?
More things to think about, but none actually answering my original question of how players build their engine. Thanks for the input though!