diff --git a/src/features/buyable.tsx b/src/features/buyable.tsx
index 30edd29..cdff9a0 100644
--- a/src/features/buyable.tsx
+++ b/src/features/buyable.tsx
@@ -1,17 +1,17 @@
+import { isArray } from "@vue/shared";
 import ClickableComponent from "features/clickables/Clickable.vue";
-import type {
-    CoercableComponent,
-    GenericComponent,
-    OptionsFunc,
-    Replace,
-    StyleValue
-} from "features/feature";
+import type { CoercableComponent, OptionsFunc, Replace, StyleValue } from "features/feature";
 import { Component, GatherProps, getUniqueID, jsx, setDefault, Visibility } from "features/feature";
-import type { Resource } from "features/resources/resource";
-import { DefaultValue, Persistent } from "game/persistence";
-import { persistent } from "game/persistence";
+import { DefaultValue, Persistent, persistent } from "game/persistence";
+import {
+    createVisibilityRequirement,
+    displayRequirements,
+    payRequirements,
+    Requirements,
+    requirementsMet
+} from "game/requirements";
 import type { DecimalSource } from "util/bignum";
-import Decimal, { format, formatWhole } from "util/bignum";
+import Decimal, { formatWhole } from "util/bignum";
 import type {
     Computable,
     GetComputableType,
@@ -37,9 +37,7 @@ export type BuyableDisplay =
 
 export interface BuyableOptions {
     visibility?: Computable<Visibility>;
-    cost?: Computable<DecimalSource>;
-    resource?: Resource;
-    canPurchase?: Computable<boolean>;
+    requirements: Requirements;
     purchaseLimit?: Computable<DecimalSource>;
     initialValue?: DecimalSource;
     classes?: Computable<Record<string, boolean>>;
@@ -47,14 +45,13 @@ export interface BuyableOptions {
     mark?: Computable<boolean | string>;
     small?: Computable<boolean>;
     display?: Computable<BuyableDisplay>;
-    onPurchase?: (cost: DecimalSource | undefined) => void;
+    onPurchase?: VoidFunction;
 }
 
 export interface BaseBuyable {
     id: string;
     amount: Persistent<DecimalSource>;
     maxed: Ref<boolean>;
-    canAfford: Ref<boolean>;
     canClick: ProcessedComputable<boolean>;
     onClick: VoidFunction;
     purchase: VoidFunction;
@@ -67,9 +64,7 @@ export type Buyable<T extends BuyableOptions> = Replace<
     T & BaseBuyable,
     {
         visibility: GetComputableTypeWithDefault<T["visibility"], Visibility.Visible>;
-        cost: GetComputableType<T["cost"]>;
-        resource: GetComputableType<T["resource"]>;
-        canPurchase: GetComputableTypeWithDefault<T["canPurchase"], Ref<boolean>>;
+        requirements: GetComputableType<T["requirements"]>;
         purchaseLimit: GetComputableTypeWithDefault<T["purchaseLimit"], Decimal>;
         classes: GetComputableType<T["classes"]>;
         style: GetComputableType<T["style"]>;
@@ -83,7 +78,6 @@ export type GenericBuyable = Replace<
     Buyable<BuyableOptions>,
     {
         visibility: ProcessedComputable<Visibility>;
-        canPurchase: ProcessedComputable<boolean>;
         purchaseLimit: ProcessedComputable<DecimalSource>;
     }
 >;
@@ -95,40 +89,31 @@ export function createBuyable<T extends BuyableOptions>(
     return createLazyProxy(() => {
         const buyable = optionsFunc();
 
-        if (buyable.canPurchase == null && (buyable.resource == null || buyable.cost == null)) {
-            console.warn(
-                "Cannot create buyable without a canPurchase property or a resource and cost property",
-                buyable
-            );
-            throw "Cannot create buyable without a canPurchase property or a resource and cost property";
-        }
-
         buyable.id = getUniqueID("buyable-");
         buyable.type = BuyableType;
         buyable[Component] = ClickableComponent;
 
         buyable.amount = amount;
         buyable.amount[DefaultValue] = buyable.initialValue ?? 0;
-        buyable.canAfford = computed(() => {
-            const genericBuyable = buyable as GenericBuyable;
-            const cost = unref(genericBuyable.cost);
-            return (
-                genericBuyable.resource != null &&
-                cost != null &&
-                Decimal.gte(genericBuyable.resource.value, cost)
-            );
-        });
-        if (buyable.canPurchase == null) {
-            buyable.canPurchase = computed(
-                () =>
-                    unref((buyable as GenericBuyable).visibility) === Visibility.Visible &&
-                    unref((buyable as GenericBuyable).canAfford) &&
-                    Decimal.lt(
-                        (buyable as GenericBuyable).amount.value,
-                        unref((buyable as GenericBuyable).purchaseLimit)
-                    )
-            );
+
+        const limitRequirement = {
+            requirementMet: computed(() =>
+                Decimal.lt(
+                    (buyable as GenericBuyable).amount.value,
+                    unref((buyable as GenericBuyable).purchaseLimit)
+                )
+            ),
+            requiresPay: false,
+            visibility: Visibility.None
+        } as const;
+        const visibilityRequirement = createVisibilityRequirement(buyable as GenericBuyable);
+        if (isArray(buyable.requirements)) {
+            buyable.requirements.unshift(visibilityRequirement);
+            buyable.requirements.push(limitRequirement);
+        } else {
+            buyable.requirements = [visibilityRequirement, buyable.requirements, limitRequirement];
         }
+
         buyable.maxed = computed(() =>
             Decimal.gte(
                 (buyable as GenericBuyable).amount.value,
@@ -144,26 +129,18 @@ export function createBuyable<T extends BuyableOptions>(
             }
             return currClasses;
         });
-        processComputable(buyable as T, "canPurchase");
-        buyable.canClick = buyable.canPurchase as ProcessedComputable<boolean>;
+        buyable.canClick = computed(() => requirementsMet(buyable.requirements));
         buyable.onClick = buyable.purchase =
             buyable.onClick ??
             buyable.purchase ??
             function (this: GenericBuyable) {
                 const genericBuyable = buyable as GenericBuyable;
-                if (!unref(genericBuyable.canPurchase)) {
+                if (!unref(genericBuyable.canClick)) {
                     return;
                 }
-                const cost = unref(genericBuyable.cost);
-                if (genericBuyable.cost != null && genericBuyable.resource != null) {
-                    genericBuyable.resource.value = Decimal.sub(
-                        genericBuyable.resource.value,
-                        // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-                        cost!
-                    );
-                    genericBuyable.amount.value = Decimal.add(genericBuyable.amount.value, 1);
-                }
-                genericBuyable.onPurchase?.(cost);
+                payRequirements(buyable.requirements);
+                genericBuyable.amount.value = Decimal.add(genericBuyable.amount.value, 1);
+                genericBuyable.onPurchase?.();
             };
         processComputable(buyable as T, "display");
         const display = buyable.display;
@@ -174,7 +151,7 @@ export function createBuyable<T extends BuyableOptions>(
                 const CurrDisplay = coerceComponent(currDisplay);
                 return <CurrDisplay />;
             }
-            if (currDisplay != null && buyable.cost != null && buyable.resource != null) {
+            if (currDisplay != null) {
                 const genericBuyable = buyable as GenericBuyable;
                 const Title = coerceComponent(currDisplay.title ?? "", "h3");
                 const Description = coerceComponent(currDisplay.description ?? "");
@@ -207,13 +184,12 @@ export function createBuyable<T extends BuyableOptions>(
                                 Currently: <EffectDisplay />
                             </div>
                         )}
-                        {genericBuyable.cost != null && !genericBuyable.maxed.value ? (
+                        {genericBuyable.maxed.value ? null : (
                             <div>
                                 <br />
-                                Cost: {format(unref(genericBuyable.cost))}{" "}
-                                {buyable.resource.displayName}
+                                {displayRequirements(genericBuyable.requirements)}
                             </div>
-                        ) : null}
+                        )}
                     </span>
                 );
             }
@@ -222,8 +198,6 @@ export function createBuyable<T extends BuyableOptions>(
 
         processComputable(buyable as T, "visibility");
         setDefault(buyable, "visibility", Visibility.Visible);
-        processComputable(buyable as T, "cost");
-        processComputable(buyable as T, "resource");
         processComputable(buyable as T, "purchaseLimit");
         setDefault(buyable, "purchaseLimit", Decimal.dInf);
         processComputable(buyable as T, "style");
diff --git a/src/features/upgrades/Upgrade.vue b/src/features/upgrades/Upgrade.vue
index 3f6903c..7c45d75 100644
--- a/src/features/upgrades/Upgrade.vue
+++ b/src/features/upgrades/Upgrade.vue
@@ -30,10 +30,8 @@ import MarkNode from "components/MarkNode.vue";
 import Node from "components/Node.vue";
 import type { StyleValue } from "features/feature";
 import { jsx, Visibility } from "features/feature";
-import type { Resource } from "features/resources/resource";
-import { displayResource } from "features/resources/resource";
 import type { GenericUpgrade } from "features/upgrades/upgrade";
-import type { DecimalSource } from "util/bignum";
+import { displayRequirements, Requirements } from "game/requirements";
 import { coerceComponent, isCoercableComponent, processedPropType, unwrapRef } from "util/vue";
 import type { Component, PropType, UnwrapRef } from "vue";
 import { defineComponent, shallowRef, toRefs, unref, watchEffect } from "vue";
@@ -50,8 +48,10 @@ export default defineComponent({
         },
         style: processedPropType<StyleValue>(String, Object, Array),
         classes: processedPropType<Record<string, boolean>>(Object),
-        resource: Object as PropType<Resource>,
-        cost: processedPropType<DecimalSource>(String, Object, Number),
+        requirements: {
+            type: Object as PropType<Requirements>,
+            required: true
+        },
         canPurchase: {
             type: processedPropType<boolean>(Boolean),
             required: true
@@ -75,7 +75,7 @@ export default defineComponent({
         MarkNode
     },
     setup(props) {
-        const { display, cost } = toRefs(props);
+        const { display, requirements, bought } = toRefs(props);
 
         const component = shallowRef<Component | string>("");
 
@@ -89,7 +89,6 @@ export default defineComponent({
                 component.value = coerceComponent(currDisplay);
                 return;
             }
-            const currCost = unwrapRef(cost);
             const Title = coerceComponent(currDisplay.title || "", "h3");
             const Description = coerceComponent(currDisplay.description, "div");
             const EffectDisplay = coerceComponent(currDisplay.effectDisplay || "");
@@ -107,14 +106,7 @@ export default defineComponent({
                                 Currently: <EffectDisplay />
                             </div>
                         ) : null}
-                        {props.resource != null ? (
-                            <>
-                                <br />
-                                Cost: {props.resource &&
-                                    displayResource(props.resource, currCost)}{" "}
-                                {props.resource?.displayName}
-                            </>
-                        ) : null}
+                        {bought.value ? null : <><br />{displayRequirements(requirements.value)}</>}
                     </span>
                 ))
             );
diff --git a/src/features/upgrades/upgrade.ts b/src/features/upgrades/upgrade.ts
index 3235e45..656d891 100644
--- a/src/features/upgrades/upgrade.ts
+++ b/src/features/upgrades/upgrade.ts
@@ -1,4 +1,11 @@
-import type { CoercableComponent, OptionsFunc, Replace, StyleValue } from "features/feature";
+import { isArray } from "@vue/shared";
+import type {
+    CoercableComponent,
+    GenericComponent,
+    OptionsFunc,
+    Replace,
+    StyleValue
+} from "features/feature";
 import {
     Component,
     findFeatures,
@@ -7,13 +14,16 @@ import {
     setDefault,
     Visibility
 } from "features/feature";
-import type { Resource } from "features/resources/resource";
 import UpgradeComponent from "features/upgrades/Upgrade.vue";
 import type { GenericLayer } from "game/layers";
 import type { Persistent } from "game/persistence";
 import { persistent } from "game/persistence";
-import type { DecimalSource } from "util/bignum";
-import Decimal from "util/bignum";
+import {
+    createVisibilityRequirement,
+    payRequirements,
+    Requirements,
+    requirementsMet
+} from "game/requirements";
 import { isFunction } from "util/common";
 import type {
     Computable,
@@ -40,10 +50,8 @@ export interface UpgradeOptions {
               effectDisplay?: CoercableComponent;
           }
     >;
+    requirements: Requirements;
     mark?: Computable<boolean | string>;
-    cost?: Computable<DecimalSource>;
-    resource?: Resource;
-    canAfford?: Computable<boolean>;
     onPurchase?: VoidFunction;
 }
 
@@ -64,9 +72,8 @@ export type Upgrade<T extends UpgradeOptions> = Replace<
         classes: GetComputableType<T["classes"]>;
         style: GetComputableType<T["style"]>;
         display: GetComputableType<T["display"]>;
+        requirements: GetComputableType<T["requirements"]>;
         mark: GetComputableType<T["mark"]>;
-        cost: GetComputableType<T["cost"]>;
-        canAfford: GetComputableTypeWithDefault<T["canAfford"], Ref<boolean>>;
     }
 >;
 
@@ -74,7 +81,6 @@ export type GenericUpgrade = Replace<
     Upgrade<UpgradeOptions>,
     {
         visibility: ProcessedComputable<Visibility>;
-        canPurchase: ProcessedComputable<boolean>;
     }
 >;
 
@@ -88,55 +94,31 @@ export function createUpgrade<T extends UpgradeOptions>(
         upgrade.type = UpgradeType;
         upgrade[Component] = UpgradeComponent;
 
-        if (upgrade.canAfford == null && (upgrade.resource == null || upgrade.cost == null)) {
-            console.warn(
-                "Error: can't create upgrade without a canAfford property or a resource and cost property",
-                upgrade
-            );
-        }
-
         upgrade.bought = bought;
-        if (upgrade.canAfford == null) {
-            upgrade.canAfford = computed(() => {
-                const genericUpgrade = upgrade as GenericUpgrade;
-                return (
-                    genericUpgrade.resource != null &&
-                    genericUpgrade.cost != null &&
-                    Decimal.gte(genericUpgrade.resource.value, unref(genericUpgrade.cost))
-                );
-            });
-        } else {
-            processComputable(upgrade as T, "canAfford");
-        }
-        upgrade.canPurchase = computed(
-            () =>
-                unref((upgrade as GenericUpgrade).visibility) === Visibility.Visible &&
-                unref((upgrade as GenericUpgrade).canAfford) &&
-                !unref(upgrade.bought)
-        );
+        upgrade.canPurchase = computed(() => requirementsMet(upgrade.requirements));
         upgrade.purchase = function () {
             const genericUpgrade = upgrade as GenericUpgrade;
             if (!unref(genericUpgrade.canPurchase)) {
                 return;
             }
-            if (genericUpgrade.resource != null && genericUpgrade.cost != null) {
-                genericUpgrade.resource.value = Decimal.sub(
-                    genericUpgrade.resource.value,
-                    unref(genericUpgrade.cost)
-                );
-            }
+            payRequirements(upgrade.requirements);
             bought.value = true;
             genericUpgrade.onPurchase?.();
         };
 
+        const visibilityRequirement = createVisibilityRequirement(upgrade as GenericUpgrade);
+        if (isArray(upgrade.requirements)) {
+            upgrade.requirements.unshift(visibilityRequirement);
+        } else {
+            upgrade.requirements = [visibilityRequirement, upgrade.requirements];
+        }
+
         processComputable(upgrade as T, "visibility");
         setDefault(upgrade, "visibility", Visibility.Visible);
         processComputable(upgrade as T, "classes");
         processComputable(upgrade as T, "style");
         processComputable(upgrade as T, "display");
         processComputable(upgrade as T, "mark");
-        processComputable(upgrade as T, "cost");
-        processComputable(upgrade as T, "resource");
 
         upgrade[GatherProps] = function (this: GenericUpgrade) {
             const {
@@ -144,8 +126,7 @@ export function createUpgrade<T extends UpgradeOptions>(
                 visibility,
                 style,
                 classes,
-                resource,
-                cost,
+                requirements,
                 canPurchase,
                 bought,
                 mark,
@@ -157,8 +138,7 @@ export function createUpgrade<T extends UpgradeOptions>(
                 visibility,
                 style: unref(style),
                 classes,
-                resource,
-                cost,
+                requirements,
                 canPurchase,
                 bought,
                 mark,
diff --git a/src/game/modifiers.tsx b/src/game/modifiers.tsx
index 851423e..830e937 100644
--- a/src/game/modifiers.tsx
+++ b/src/game/modifiers.tsx
@@ -14,8 +14,7 @@ import { computed, unref } from "vue";
  * An object that can be used to apply or unapply some modification to a number.
  * Being reversible requires the operation being invertible, but some features may rely on that.
  * Descriptions can be optionally included for displaying them to the player.
- * The built-in modifier creators are designed to display the modifiers using.
- * {@link createModifierSection}.
+ * The built-in modifier creators are designed to display the modifiers using {@link createModifierSection}.
  */
 export interface Modifier {
     /** Applies some operation on the input and returns the result. */
diff --git a/src/game/requirements.tsx b/src/game/requirements.tsx
new file mode 100644
index 0000000..607800b
--- /dev/null
+++ b/src/game/requirements.tsx
@@ -0,0 +1,165 @@
+import { isArray } from "@vue/shared";
+import { CoercableComponent, jsx, JSXFunction, setDefault, Visibility } from "features/feature";
+import { displayResource, Resource } from "features/resources/resource";
+import Decimal, { DecimalSource } from "lib/break_eternity";
+import {
+    Computable,
+    convertComputable,
+    processComputable,
+    ProcessedComputable
+} from "util/computed";
+import { createLazyProxy } from "util/proxies";
+import { joinJSX, renderJSX } from "util/vue";
+import { computed, unref } from "vue";
+
+/**
+ * An object that can be used to describe a requirement to perform some purchase or other action.
+ * @see {@link createCostRequirement}
+ */
+export interface Requirement {
+    /** The display for this specific requirement. This is used for displays multiple requirements condensed. Required if {@link visibility} can be {@link Visibility.Visible}. */
+    partialDisplay?: JSXFunction;
+    /** The display for this specific requirement. Required if {@link visibility} can be {@link Visibility.Visible}. */
+    display?: JSXFunction;
+    visibility: ProcessedComputable<Visibility.Visible | Visibility.None>;
+    requirementMet: ProcessedComputable<boolean>;
+    requiresPay: ProcessedComputable<boolean>;
+    pay?: VoidFunction;
+}
+
+export type Requirements = Requirement | Requirement[];
+
+export interface CostRequirementOptions {
+    resource: Resource;
+    cost: Computable<DecimalSource>;
+    visibility?: Computable<Visibility.Visible | Visibility.None>;
+    requiresPay?: ProcessedComputable<boolean>;
+    pay?: VoidFunction;
+}
+
+export function createCostRequirement<T extends CostRequirementOptions>(
+    optionsFunc: () => T
+): Requirement {
+    return createLazyProxy(() => {
+        const req = optionsFunc() as T & Partial<Requirement>;
+
+        req.requirementMet = computed(() =>
+            Decimal.gte(req.resource.value, unref(req.cost as ProcessedComputable<DecimalSource>))
+        );
+
+        req.partialDisplay = jsx(() => (
+            <span
+                style={
+                    unref(req.requirementMet as ProcessedComputable<boolean>)
+                        ? ""
+                        : "color: var(--danger)"
+                }
+            >
+                {displayResource(
+                    req.resource,
+                    unref(req.cost as ProcessedComputable<DecimalSource>)
+                )}{" "}
+                {req.resource.displayName}
+            </span>
+        ));
+        req.display = jsx(() => (
+            <div>
+                {unref(req.requiresPay as ProcessedComputable<boolean>) ? "Costs: " : "Requires: "}
+                {displayResource(
+                    req.resource,
+                    unref(req.cost as ProcessedComputable<DecimalSource>)
+                )}{" "}
+                {req.resource.displayName}
+            </div>
+        ));
+
+        processComputable(req as T, "visibility");
+        setDefault(req, "visibility", Visibility.Visible);
+        processComputable(req as T, "cost");
+        processComputable(req as T, "requiresPay");
+        setDefault(req, "requiresPay", true);
+        setDefault(req, "pay", function () {
+            req.resource.value = Decimal.sub(
+                req.resource.value,
+                unref(req.cost as ProcessedComputable<DecimalSource>)
+            ).max(0);
+        });
+
+        return req as Requirement;
+    });
+}
+
+export function createVisibilityRequirement(feature: {
+    visibility: ProcessedComputable<Visibility>;
+}): Requirement {
+    return createLazyProxy(() => ({
+        requirementMet: computed(() => unref(feature.visibility) === Visibility.Visible),
+        visibility: Visibility.None,
+        requiresPay: false
+    }));
+}
+
+export function createBooleanRequirement(
+    requirement: Computable<boolean>,
+    display?: CoercableComponent
+): Requirement {
+    return createLazyProxy(() => ({
+        requirementMet: convertComputable(requirement),
+        partialDisplay: display == null ? undefined : jsx(() => renderJSX(display)),
+        display: display == null ? undefined : jsx(() => <>Req: {renderJSX(display)}</>),
+        visibility: display == null ? Visibility.None : Visibility.Visible,
+        requiresPay: false
+    }));
+}
+
+export function requirementsMet(requirements: Requirements) {
+    if (isArray(requirements)) {
+        return requirements.every(r => unref(r.requirementMet));
+    }
+    return unref(requirements.requirementMet);
+}
+
+export function displayRequirements(requirements: Requirements) {
+    if (isArray(requirements)) {
+        requirements = requirements.filter(r => unref(r.visibility) === Visibility.Visible);
+        if (requirements.length === 1) {
+            requirements = requirements[0];
+        }
+    }
+    if (isArray(requirements)) {
+        requirements = requirements.filter(r => "partialDisplay" in r);
+        const withCosts = requirements.filter(r => unref(r.requiresPay));
+        const withoutCosts = requirements.filter(r => !unref(r.requiresPay));
+        return (
+            <>
+                {withCosts.length > 0 ? (
+                    <div>
+                        Costs:{" "}
+                        {joinJSX(
+                            withCosts.map(r => r.partialDisplay!()),
+                            <>, </>
+                        )}
+                    </div>
+                ) : null}
+                {withoutCosts.length > 0 ? (
+                    <div>
+                        Requires:{" "}
+                        {joinJSX(
+                            withoutCosts.map(r => r.partialDisplay!()),
+                            <>, </>
+                        )}
+                    </div>
+                ) : null}
+            </>
+        );
+    }
+    return requirements.display?.() ?? <></>;
+}
+
+export function payRequirements(requirements: Requirements) {
+    if (isArray(requirements)) {
+        requirements.filter(r => unref(r.requiresPay)).forEach(r => r.pay?.());
+    } else if (unref(requirements.requiresPay)) {
+        requirements.pay?.();
+    }
+}