Wiki game ideas

When you summon shit, what it does is largely by popular consensus. The summoner suggests abilities that seems appropriate, and other players agree or disagree based on what they think is reasonable. If the majority don't think the idea is workable, the next player in the turn order suggests abilities and the process repeats.

Creatures – Any human, group, animal, or other such thing that could feasibly engage in combat
Creatures have attack and defence based on what they are, with the following list demonstrating roughly where that shit should fall.

0 – An extremely small animal, a human with no combat ability at all
1 – An untrained human, a relatively non-threatening animal
2 – An athlete, moderately threatening animal, a group of untrained humans
3 – A trained warrior, a threatening animal, a group of athletes
10 – A kaiju
20 – I don't even know, but something scary. Deathstar?

Obviously this can vary a bit. In addition, creatures can have other effects, which could be literally fucking anything. For the sake of simplicity, let's say on a turn a creature can EITHER attack or use an activated effect. As for combat we can either do MtG rules (Creatures attack players, and the defending players can choose to have untapped creatures block an attack) or YGO rules (Creatures can attack either creatures or players, but cannot target players while they control any creatures)

Locations – Self-explanatory
Locations act as battlefields. They can have effects, usually ones that are resource-producing or global passives. Maybe a mechanic where you can sacrifice (or maybe just tap?) a Location for an extra summon. If you want to really press locations as resources, you could have the number of creatures you can control limited by the number of locations you control.

Equipment – Weapons, tools, devices, vehicles, food, resources. Basically anything inanimate too small to be a location
Equipment is stuff that creatures can use. Equipment should generally be buffing the equipped creature, but can have any effect. An absolute rule though is that equipment has to be equipped to a creature to be of use. At the start of your turn, you can attach equipment to a creature. If the equipped creature dies, the equipment is dropped.

Auras – Ideologies, concepts, works of fiction, companies. Anything ephemeral.
Auras are similar to locations in that they generally grant passive bonuses as their effect. Alternately, they can grant a single-use effect that can be kept back and played at any time, even during an opponent's turn. After these effects are used, they are discarded.

Example Creature:
José Ramón Rodríguez Gómez, Goalkeeper
A1/D2
Neither you nor any creatures you control can be attacked while you control José

Example Aura:
Robinson's joint consistency theorem
Discard: Summon a single mathemetician or mathematical concept

Example Location:
Maroviro
Tap: Summon rice, peanuts, or cassava

Example Equipment
HMS Hunter
+1/+2 to Equipped Creature
Equipped Creature may attack a player directly if they control a body of water and no naval units
+1/+0 against Spanish Creatures