The Rule of Tincture is defined as follows: "Colour may not be placed on Colour, nor Metal on Metal." This Rule is generally inviolable, with certain explicit exceptions as outlined below.

1. The so-called "simple" Ordinaries (Pale, Fess, Bend, Bend Sinister, Cross, Saltire, Chevron, Chevron Inverted, Pall, and Pall Inverted) may be used in the following manner so long as they contain no complex lines:
1. Gules Ordinary on a Sable or Azure field;
2. Sable or Azure Ordinary on a Gules field.
3. Ordinaries used in this fashion may be charged, except where such charging would violate the Rule of Tincture.
4. Ordinaries used in this fashion may not be cotised in tinctures which violate the Rule of Tincture.
2. Field divisions are considered as "tincture next to tincture" and as such are not considered subject to this Rule. However, this category is subject to the following restrictions:
1. Field divisions of up to four parts (per pale, quarterly, per saltire, et cetera) may consist of two Colours or two Metals. There are two exceptions to this:
1. The lines of division must be plain line; no complex lines will be allowed. Divisions with complex lines must be comprised of one Colour and one Metal.
2. Per pall and per pall inverted field divisions must contain either two Colours and one Metal or two Metals and one Colour. See the Appendix for specific examples.
2. Field divisions of more than four parts (gyronny, checky, bendy, paly, et cetera) must be comprised of one Colour and one Metal.
3. Vert mounts (bases enarched) may be placed on plain Azure fields. The converse is not permitted. The line must be plain and not complex.

4. Furs.
1. Furs are defined as being of two tinctures, one Metal and one Colour. The tincture Sable, since it is a solid color, is not a Fur.
2. For the purposes of this Rule, Ermine and its variants are to be considered tinctured the same as their background tincture. Erminois is considered equivalent to Or, Counter-Ermine (also known as Ermines) is considered Sable, et cetera. Therefore, an Or charge may not be placed on Ermine or Erminois, and so forth, except under the conditions specified in this Rule.
3. Ermine variants are created by strewing a field with ermine spots. This ermining is restricted to the Rule of Tincture; Metals may only be ermined with Colours, and Colours may only be ermined with Metals. Purpure ermined Or is acceptable; Azure ermined Gules is not.
4. For the purposes of conflict, Ermine and its variants are to be considered 1 clear difference (CD) from their background tincture. Ermine is 1 CD from Argent, Gules ermined Or is 1 CD from Gules, and so forth. (formerly I.D.)
5. For the purposes of this Rule, Vair and its variants are considered neutral and may be combined with any other tincture, except the tinctures that make up the Vair or Vair variant. Therefore, a charge vairy Argent and Gules may not be placed on Argent or Gules, and so forth. (formerly I.E.)
6. There are no restrictions on the use of furs of any tincture combination, except where noted above.

5. Augmentations granted by any Crown are exempt from this Rule.
6. Small details of a charge, such as eyes, tongue, or claws on a beast, are exempt from this Rule.
7. Metal on metal is reserved specifically to the Imperial Crown and its agents.
8. Any violations to the Rule of Tincture other than those explicitly permitted in these Rules must be adequately documented as described in Rule XIX.
9. The only acceptable tinctures are as follows: Argent and Or, the "Metals"; and Sable, Gules, Azure, Vert, and Purpure, the "Colours".
10. There are no restrictions on any tincture or combination of tinctures, except that the Rule of Tincture may not be violated except under the conditions listed above.